diff --git a/.ci/check-abi b/.ci/check-abi
new file mode 100755
index 00000000..06eb1aca
--- /dev/null
+++ b/.ci/check-abi
@@ -0,0 +1,113 @@
+#!/usr/bin/python3
+
+
+import argparse
+import contextlib
+import os
+import shutil
+import subprocess
+import sys
+
+
+def format_title(title):
+    box = {
+        'tl': '╔', 'tr': '╗', 'bl': '╚', 'br': '╝', 'h': '═', 'v': '║',
+    }
+    hline = box['h'] * (len(title) + 2)
+
+    return '\n'.join([
+        f"{box['tl']}{hline}{box['tr']}",
+        f"{box['v']} {title} {box['v']}",
+        f"{box['bl']}{hline}{box['br']}",
+    ])
+
+
+def rm_rf(path):
+    try:
+        shutil.rmtree(path)
+    except FileNotFoundError:
+        pass
+
+
+def sanitize_path(name):
+    return name.replace('/', '-')
+
+
+def get_current_revision():
+    revision = subprocess.check_output(['git', 'rev-parse', '--abbrev-ref', 'HEAD'],
+                                       encoding='utf-8').strip()
+
+    if revision == 'HEAD':
+        # This is a detached HEAD, get the commit hash
+        revision = subprocess.check_output(['git', 'rev-parse', 'HEAD']).strip().decode('utf-8')
+
+    return revision
+
+
+@contextlib.contextmanager
+def checkout_git_revision(revision):
+    current_revision = get_current_revision()
+    subprocess.check_call(['git', 'checkout', '-q', revision])
+
+    try:
+        yield
+    finally:
+        subprocess.check_call(['git', 'checkout', '-q', current_revision])
+
+
+def build_install(revision):
+    build_dir = '_build'
+    dest_dir = os.path.abspath(sanitize_path(revision))
+    print(format_title(f'# Building and installing {revision} in {dest_dir}'),
+          end='\n\n', flush=True)
+
+    with checkout_git_revision(revision):
+        rm_rf(build_dir)
+        rm_rf(revision)
+
+        subprocess.check_call(['meson', build_dir,
+                               '--prefix=/usr', '--libdir=lib',
+                               '-Dx11-examples=false', '-Ddoc=false', '-Dgtk-examples=false'])
+        subprocess.check_call(['ninja', '-v', '-C', build_dir])
+        subprocess.check_call(['ninja', '-v', '-C', build_dir, 'install'],
+                              env={'DESTDIR': dest_dir})
+
+    return dest_dir
+
+
+def compare(old_tree, new_tree):
+    print(format_title(f'# Comparing the two ABIs'), end='\n\n', flush=True)
+
+    old_headers = os.path.join(old_tree, 'usr', 'include')
+    old_lib = os.path.join(old_tree, 'usr', 'lib', 'libfprint.so')
+
+    new_headers = os.path.join(new_tree, 'usr', 'include')
+    new_lib = os.path.join(new_tree, 'usr', 'lib', 'libfprint.so')
+
+    subprocess.check_call([
+        'abidiff', '--headers-dir1', old_headers, '--headers-dir2', new_headers,
+        '--drop-private-types', '--fail-no-debug-info', '--no-added-syms', old_lib, new_lib])
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument('old', help='the previous revision, considered the reference')
+    parser.add_argument('new', help='the new revision, to compare to the reference')
+
+    args = parser.parse_args()
+
+    if args.old == args.new:
+        print("Let's not waste time comparing something to itself")
+        sys.exit(0)
+
+    old_tree = build_install(args.old)
+    new_tree = build_install(args.new)
+
+    try:
+        compare(old_tree, new_tree)
+
+    except Exception:
+        sys.exit(1)
+
+    print(f'Hurray! {args.old} and {args.new} are ABI-compatible!')
diff --git a/HACKING.md b/HACKING.md
index e43cbf2b..21e17a4b 100644
--- a/HACKING.md
+++ b/HACKING.md
@@ -3,8 +3,29 @@
 ## GLib
 
 Although the library uses GLib internally, libfprint is designed to provide
-a completely neutral interface to it's application users. So, the public
-APIs should never return GLib data types or anything like that.
+a completely neutral interface to its application users. So, the public
+APIs should never return GLib data types.
+
+## License clarification
+
+Although this library's license could allow for shims that hook up into
+proprietary blobs to add driver support for some unsupported devices, the
+intent of the original authors, and of current maintainers of the library,
+was for this license to allow _integration into_ proprietary stacks, not
+_integration of_ proprietary code in the library.
+
+As such, no code to integrate proprietary drivers will be accepted in libfprint
+upstream. Proprietary drivers would make it impossible to debug problems in
+libfprint, as we wouldn't know what the proprietary driver does behind the
+library's back. The closed source nature of drivers is usually used to hide
+parts of the hardware setup, such as encryption keys, or protocols, in order
+to protect the hardware's integrity. Unfortunately, this is only [security through
+obscurity](https://en.wikipedia.org/wiki/Security_through_obscurity).
+
+We however encourage potential contributors to take advantage of libfprint's
+source availability to create such shims to make it easier to reverse-engineer
+proprietary drivers in order to create new free software drivers, to the extent
+permitted by local laws.
 
 ## Two-faced-ness
 
diff --git a/NEWS b/NEWS
index 34d6cc2e..ba0ccc3d 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,33 @@
 This file lists notable changes in each release. For the full history of all
 changes, see ChangeLog.
 
+2019-08-08: v1.0 release
+* Library:
+  - Add guards to the public API and require GLib 2.50
+  - Deprecate print storage API
+  - Better documentation for fp_discover_devs()
+  - Remove unused internal fpi_timeout_cancel_for_dev()
+  - Remove state from fp_img_driver activate handler
+  - Bug fixes related to restarting a failed verification immediately
+
+* Drivers:
+  - The Elan driver received a lot of bug fixes including a fix for a
+    hang when verifying prints with fprintd, quirks for some devices,
+    a memory leak fix and support for 04f3:0c42
+  - Fix a probable crash in all the AES drivers
+  - Add support for Lenovo Preferred Pro Keyboard (KUF1256) to vfs5011
+  - Prevent hang during enroll process in etes603 driver
+  - Fix possible integer overflow in uru4000
+  - Work-around SELinux AVC warnings when uru4000 driver starts
+  - Remove long-unmaintained and broken fdu2000 driver
+
+* Tools/Examples:
+  - Fix examples not working due to an overly strict check
+  - Fix crash in GTK demo when there's no supported devices
+  - Disable GTK demo until we have a USB Flatpak portal
+  - Remove sleep() in enroll example which caused a crash in some drivers
+  - Add a simple storage implementation example
+
 2018-12-14: v0.99.0 release
 * Library:
   - All the internal API for device driver writers is now covered by the
diff --git a/code-of-conduct.md b/code-of-conduct.md
new file mode 100644
index 00000000..a429a426
--- /dev/null
+++ b/code-of-conduct.md
@@ -0,0 +1,3 @@
+This project and its community follow the [Freedesktop.org code of conduct]
+
+[Freedesktop.org code of conduct]: https://www.freedesktop.org/wiki/CodeOfConduct/
diff --git a/demo/gtk-libfprint-test.c b/demo/gtk-libfprint-test.c
index b23e38dd..d0dd0c1e 100644
--- a/demo/gtk-libfprint-test.c
+++ b/demo/gtk-libfprint-test.c
@@ -473,8 +473,17 @@ libfprint_demo_window_init (LibfprintDemoWindow *window)
 	setup_pollfds ();
 
 	discovered_devs = fp_discover_devs();
-	if (!discovered_devs)
+	if (!discovered_devs) {
+		libfprint_demo_set_mode (window, ERROR_MODE);
 		return;
+	}
+
+	/* Empty list? */
+	if (discovered_devs[0] == NULL) {
+		fp_dscv_devs_free (discovered_devs);
+		libfprint_demo_set_mode (window, EMPTY_MODE);
+		return;
+	}
 
 	if (!fp_driver_supports_imaging(fp_dscv_dev_get_driver(discovered_devs[0]))) {
 		libfprint_demo_set_mode (window, NOIMAGING_MODE);
diff --git a/examples/enroll.c b/examples/enroll.c
index 4eea39ad..9814f68e 100644
--- a/examples/enroll.c
+++ b/examples/enroll.c
@@ -24,6 +24,8 @@
 
 #include <libfprint/fprint.h>
 
+#include "storage.h"
+
 struct fp_dscv_dev *discover_device(struct fp_dscv_dev **discovered_devs)
 {
 	struct fp_dscv_dev *ddev = discovered_devs[0];
@@ -45,8 +47,7 @@ struct fp_print_data *enroll(struct fp_dev *dev) {
 
 	do {
 		struct fp_img *img = NULL;
-	
-		sleep(1);
+
 		printf("\nScan your finger now.\n");
 
 		r = fp_enroll_finger_img(dev, &enrolled_print, &img);
@@ -143,7 +144,7 @@ int main(void)
 	if (!data)
 		goto out_close;
 
-	r = fp_print_data_save(data, RIGHT_INDEX);
+	r = print_data_save(data, RIGHT_INDEX);
 	if (r < 0)
 		fprintf(stderr, "Data save failed, code %d\n", r);
 
diff --git a/examples/meson.build b/examples/meson.build
index cba326fb..7596be64 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -2,8 +2,8 @@
 examples = [ 'verify_live', 'enroll', 'verify', 'img_capture' ]
 foreach example: examples
     executable(example,
-               example + '.c',
-               dependencies: libfprint_dep,
+               [example + '.c', 'storage.c'],
+               dependencies: [libfprint_dep, glib_dep],
                include_directories: [
                  root_inc,
                ],
diff --git a/examples/storage.c b/examples/storage.c
new file mode 100644
index 00000000..aa399e0f
--- /dev/null
+++ b/examples/storage.c
@@ -0,0 +1,136 @@
+/*
+ * Trivial storage driver for example programs
+ *
+ * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <glib.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <libfprint/fprint.h>
+
+#define STORAGE_FILE "test-storage.variant"
+
+static char *
+get_print_data_descriptor (struct fp_print_data *data, struct fp_dev *dev, enum fp_finger finger)
+{
+	gint drv_id;
+	gint devtype;
+
+	if (data) {
+		drv_id = fp_print_data_get_driver_id (data);
+		devtype = fp_print_data_get_devtype (data);
+	} else {
+		drv_id = fp_driver_get_driver_id(fp_dev_get_driver (dev));
+		devtype = fp_dev_get_devtype (dev);
+	}
+
+	return g_strdup_printf("%x/%08x/%x",
+			       drv_id,
+			       devtype,
+			       finger);
+}
+
+static GVariantDict*
+load_data(void)
+{
+	GVariantDict *res;
+	GVariant *var;
+	gchar *contents = NULL;
+	gssize length = 0;
+
+	if (!g_file_get_contents (STORAGE_FILE, &contents, &length, NULL)) {
+		g_warning ("Error loading storage, assuming it is empty");
+		return g_variant_dict_new(NULL);
+	}
+
+	var = g_variant_new_from_data (G_VARIANT_TYPE_VARDICT, contents, length, FALSE, NULL, NULL);
+
+	res = g_variant_dict_new(var);
+	g_variant_unref(var);
+	return res;
+}
+
+static int
+save_data(GVariant *data)
+{
+	const gchar *contents = NULL;
+	gsize length;
+
+	length = g_variant_get_size(data);
+	contents = (gchar*) g_variant_get_data (data);
+
+	if (!g_file_set_contents (STORAGE_FILE, contents, length, NULL)) {
+		g_warning ("Error saving storage,!");
+		return -1;
+	}
+
+	g_variant_ref_sink(data);
+	g_variant_unref(data);
+
+	return 0;
+}
+
+int
+print_data_save(struct fp_print_data *fp_data, enum fp_finger finger)
+{
+	gchar *descr = get_print_data_descriptor (fp_data, NULL, finger);
+	GVariantDict *dict;
+	GVariant *val;
+	guchar *data;
+	gsize size;
+	int res;
+
+	dict = load_data();
+
+	size = fp_print_data_get_data(fp_data, &data);
+	val = g_variant_new_fixed_array (G_VARIANT_TYPE("y"), data, size, 1);
+	g_variant_dict_insert_value (dict, descr, val);
+
+	res = save_data(g_variant_dict_end(dict));
+	g_variant_dict_unref(dict);
+
+	return res;
+}
+
+struct fp_print_data*
+print_data_load(struct fp_dev *dev, enum fp_finger finger)
+{
+	gchar *descr = get_print_data_descriptor (NULL, dev, finger);
+	GVariantDict *dict;
+	guchar *stored_data;
+	gsize stored_len;
+	GVariant *val;
+	struct fp_print_data *res = NULL;
+
+	dict = load_data();
+	val = g_variant_dict_lookup_value (dict, descr, G_VARIANT_TYPE ("ay"));
+
+	if (val) {
+		stored_data = (guchar*) g_variant_get_fixed_array (val, &stored_len, 1);
+		res = fp_print_data_from_data(stored_data, stored_len);
+
+		g_variant_unref(val);
+	}
+
+	g_variant_dict_unref(dict);
+	g_free(descr);
+
+	return res;
+}
diff --git a/examples/storage.h b/examples/storage.h
new file mode 100644
index 00000000..fc86813e
--- /dev/null
+++ b/examples/storage.h
@@ -0,0 +1,27 @@
+/*
+ * Trivial storage driver for example programs
+ *
+ * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __STORAGE_H
+#define __STORAGE_H
+
+int print_data_save(struct fp_print_data *fp_data, enum fp_finger finger);
+struct fp_print_data* print_data_load(struct fp_dev *dev, enum fp_finger finger);
+
+#endif /* __STORAGE_H */
diff --git a/examples/verify.c b/examples/verify.c
index 26566edd..38b925c5 100644
--- a/examples/verify.c
+++ b/examples/verify.c
@@ -24,6 +24,8 @@
 
 #include <libfprint/fprint.h>
 
+#include "storage.h"
+
 struct fp_dscv_dev *discover_device(struct fp_dscv_dev **discovered_devs)
 {
 	struct fp_dscv_dev *ddev = discovered_devs[0];
@@ -117,8 +119,8 @@ int main(void)
 	printf("Opened device. Loading previously enrolled right index finger "
 		"data...\n");
 
-	r = fp_print_data_load(dev, RIGHT_INDEX, &data);
-	if (r != 0) {
+	data = print_data_load(dev, RIGHT_INDEX);
+	if (!data) {
 		fprintf(stderr, "Failed to load fingerprint, error %d\n", r);
 		fprintf(stderr, "Did you remember to enroll your right index finger "
 			"first?\n");
diff --git a/examples/verify_live.c b/examples/verify_live.c
index 82ec2abc..4c02ff2f 100644
--- a/examples/verify_live.c
+++ b/examples/verify_live.c
@@ -43,7 +43,6 @@ struct fp_print_data *enroll(struct fp_dev *dev) {
 		"complete the process.\n", fp_dev_get_nr_enroll_stages(dev));
 
 	do {
-		sleep(1);
 		printf("\nScan your finger now.\n");
 		r = fp_enroll_finger(dev, &enrolled_print);
 		if (r < 0) {
diff --git a/libfprint/drivers/aes1610.c b/libfprint/drivers/aes1610.c
index 1e7b3b9b..df5b5695 100644
--- a/libfprint/drivers/aes1610.c
+++ b/libfprint/drivers/aes1610.c
@@ -404,7 +404,7 @@ static unsigned char list_BD_values[10] = {
 /*
  * Adjust the gain according to the histogram data
  * 0xbd, 0xbe, 0x29 and 0x2A registers are affected
- * Returns 0 if no problem occured
+ * Returns 0 if no problem occurred
  * TODO: This is a basic support for gain. It needs testing/tweaking.  */
 static int adjust_gain(unsigned char *buffer, int status)
 {
@@ -412,7 +412,7 @@ static int adjust_gain(unsigned char *buffer, int status)
 	static int pos_list_BE = 0;
 	static int pos_list_BD = 0;
 
-	// This is the first adjustement (we begin acquisition)
+	// This is the first adjustment (we begin acquisition)
 	// We adjust strip_scan_reqs for future strips and capture_reqs that is sent just after this step
 	if (status == GAIN_STATUS_FIRST) {
 		if (buffer[1] > 0x78) { // maximum gain needed
@@ -534,7 +534,7 @@ static void restore_gain(void)
 
 /* capture SM movement:
  * request and read strip,
- * jump back to request UNLESS theres no finger, in which case exit SM,
+ * jump back to request UNLESS there's no finger, in which case exit SM,
  * report lack of finger presence, and move to finger detection */
 
 enum capture_states {
@@ -728,7 +728,7 @@ static void activate_run_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_dat
 	struct fp_img_dev *dev = user_data;
 
 	/* activation on aes1610 seems much more straightforward compared to aes2501 */
-	/* verify theres anything missing here */
+	/* verify there's anything missing here */
 	switch (fpi_ssm_get_cur_state(ssm)) {
 	case WRITE_INIT:
 		fp_dbg("write init");
@@ -749,7 +749,7 @@ static void activate_sm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_d
 	fpi_ssm_free(ssm);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct aes1610_dev *aesdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), activate_run_state,
diff --git a/libfprint/drivers/aes2501.c b/libfprint/drivers/aes2501.c
index 2a031732..91e02a39 100644
--- a/libfprint/drivers/aes2501.c
+++ b/libfprint/drivers/aes2501.c
@@ -415,7 +415,7 @@ static struct aes_regwrite strip_scan_reqs[] = {
 /* capture SM movement:
  * write reqs and read data 1 + 2,
  * request and read strip,
- * jump back to request UNLESS theres no finger, in which case exit SM,
+ * jump back to request UNLESS there's no finger, in which case exit SM,
  * report lack of finger presence, and move to finger detection */
 
 enum capture_states {
@@ -792,7 +792,7 @@ static void activate_sm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_d
 	fpi_ssm_free(ssm);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct aes2501_dev *aesdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), activate_run_state,
diff --git a/libfprint/drivers/aes2501.h b/libfprint/drivers/aes2501.h
index 9f2f1b6e..19adcc90 100644
--- a/libfprint/drivers/aes2501.h
+++ b/libfprint/drivers/aes2501.h
@@ -109,7 +109,7 @@ enum aes2501_mesure_drive {
 
 /* Select (1=square | 0=sine) wave drive during measure */
 #define AES2501_MEASDRV_SQUARE		0x20
-/* 0 = use mesure drive setting, 1 = when sine wave is selected */
+/* 0 = use measure drive setting, 1 = when sine wave is selected */
 #define AES2501_MEASDRV_MEASURE_SQUARE	0x10
 
 enum aes2501_measure_freq {
diff --git a/libfprint/drivers/aes2550.c b/libfprint/drivers/aes2550.c
index ce5b6c2b..72a86132 100644
--- a/libfprint/drivers/aes2550.c
+++ b/libfprint/drivers/aes2550.c
@@ -447,7 +447,7 @@ static void init_read_data_cb(struct libusb_transfer *transfer)
 }
 
 /* TODO: use calibration table, datasheet is rather terse on that
- * need more info for implementaion */
+ * need more info for implementation */
 static void calibrate_read_data_cb(struct libusb_transfer *transfer)
 {
 	fpi_ssm *ssm = transfer->user_data;
@@ -541,7 +541,7 @@ static void activate_sm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_d
 	fpi_ssm_free(ssm);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), activate_run_state,
 		ACTIVATE_NUM_STATES, dev);
diff --git a/libfprint/drivers/aes3k.c b/libfprint/drivers/aes3k.c
index 59c91bcc..ddb94c9b 100644
--- a/libfprint/drivers/aes3k.c
+++ b/libfprint/drivers/aes3k.c
@@ -137,7 +137,7 @@ static void init_reqs_cb(struct fp_img_dev *dev, int result, void *user_data)
 		do_capture(dev);
 }
 
-int aes3k_dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+int aes3k_dev_activate(struct fp_img_dev *dev)
 {
 	struct aes3k_dev *aesdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	aes_write_regv(dev, aesdev->init_reqs, aesdev->init_reqs_len, init_reqs_cb, NULL);
diff --git a/libfprint/drivers/aes3k.h b/libfprint/drivers/aes3k.h
index 98750ede..a54199d0 100644
--- a/libfprint/drivers/aes3k.h
+++ b/libfprint/drivers/aes3k.h
@@ -52,7 +52,7 @@ struct aes3k_dev {
 };
 
 
-int aes3k_dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state);
+int aes3k_dev_activate(struct fp_img_dev *dev);
 void aes3k_dev_deactivate(struct fp_img_dev *dev);
 
 #endif
diff --git a/libfprint/drivers/aeslib.c b/libfprint/drivers/aeslib.c
index 1ff3986d..24e307ce 100644
--- a/libfprint/drivers/aeslib.c
+++ b/libfprint/drivers/aeslib.c
@@ -53,12 +53,15 @@ static void write_regv_trf_complete(struct libusb_transfer *transfer)
 {
 	struct write_regv_data *wdata = transfer->user_data;
 
-	if (transfer->status != LIBUSB_TRANSFER_COMPLETED)
+	if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 		wdata->callback(wdata->imgdev, -EIO, wdata->user_data);
-	else if (transfer->length != transfer->actual_length)
+		g_free(wdata);
+	} else if (transfer->length != transfer->actual_length) {
 		wdata->callback(wdata->imgdev, -EPROTO, wdata->user_data);
-	else
+		g_free(wdata);
+	} else {
 		continue_write_regv(wdata);
+	}
 
 	g_free(transfer->buffer);
 	libusb_free_transfer(transfer);
@@ -109,6 +112,7 @@ static void continue_write_regv(struct write_regv_data *wdata)
 		if (offset >= wdata->num_regs) {
 			fp_dbg("all registers written");
 			wdata->callback(wdata->imgdev, 0, wdata->user_data);
+			g_free(wdata);
 			return;
 		}
 		if (wdata->regs[offset].reg)
@@ -132,6 +136,7 @@ static void continue_write_regv(struct write_regv_data *wdata)
 	r = do_write_regv(wdata, upper_bound);
 	if (r < 0) {
 		wdata->callback(wdata->imgdev, r, wdata->user_data);
+		g_free(wdata);
 		return;
 	}
 
@@ -155,8 +160,6 @@ void aes_write_regv(struct fp_img_dev *dev, const struct aes_regwrite *regs,
 	wdata->callback = callback;
 	wdata->user_data = user_data;
 	continue_write_regv(wdata);
-
-	g_free(wdata);
 }
 
 unsigned char aes_get_pixel(struct fpi_frame_asmbl_ctx *ctx,
diff --git a/libfprint/drivers/aesx660.c b/libfprint/drivers/aesx660.c
index 852c7509..47da51f5 100644
--- a/libfprint/drivers/aesx660.c
+++ b/libfprint/drivers/aesx660.c
@@ -589,7 +589,7 @@ static void activate_sm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_d
 		start_finger_detection(dev);
 }
 
-int aesX660_dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+int aesX660_dev_activate(struct fp_img_dev *dev)
 {
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), activate_run_state,
 		ACTIVATE_NUM_STATES, dev);
diff --git a/libfprint/drivers/aesx660.h b/libfprint/drivers/aesx660.h
index 2106ca2d..8d8f3501 100644
--- a/libfprint/drivers/aesx660.h
+++ b/libfprint/drivers/aesx660.h
@@ -116,7 +116,7 @@ static const unsigned char calibrate_cmd[] = {
 	0x06,
 };
 
-int aesX660_dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state);
+int aesX660_dev_activate(struct fp_img_dev *dev);
 void aesX660_dev_deactivate(struct fp_img_dev *dev);
 
 #endif
diff --git a/libfprint/drivers/driver_ids.h b/libfprint/drivers/driver_ids.h
index 8839a744..012a3d06 100644
--- a/libfprint/drivers/driver_ids.h
+++ b/libfprint/drivers/driver_ids.h
@@ -27,7 +27,7 @@ enum {
 	AES2501_ID	= 4,
 	UPEKTC_ID	= 5,
 	AES1610_ID	= 6,
-	FDU2000_ID	= 7,
+	/* FDU2000_ID	= 7, */
 	VCOM5S_ID	= 8,
 	UPEKSONLY_ID	= 9,
 	VFS101_ID	= 10,
diff --git a/libfprint/drivers/elan.c b/libfprint/drivers/elan.c
index ed474b05..e9dad43e 100644
--- a/libfprint/drivers/elan.c
+++ b/libfprint/drivers/elan.c
@@ -293,23 +293,22 @@ static void elan_process_frame_thirds(unsigned short *raw_frame,
 static void elan_submit_image(struct fp_img_dev *dev)
 {
 	struct elan_dev *elandev = FP_INSTANCE_DATA(FP_DEV(dev));
+	int num_frames;
+	GSList *raw_frames;
 	GSList *frames = NULL;
 	struct fp_img *img;
 
 	G_DEBUG_HERE();
 
-	for (int i = 0; i < ELAN_SKIP_LAST_FRAMES; i++)
-		elandev->frames = g_slist_next(elandev->frames);
-	elandev->num_frames -= ELAN_SKIP_LAST_FRAMES;
+	num_frames = elandev->num_frames - ELAN_SKIP_LAST_FRAMES;
+	raw_frames = g_slist_nth(elandev->frames, ELAN_SKIP_LAST_FRAMES);
 
 	assembling_ctx.frame_width = elandev->frame_width;
 	assembling_ctx.frame_height = elandev->frame_height;
 	assembling_ctx.image_width = elandev->frame_width * 3 / 2;
-	g_slist_foreach(elandev->frames, (GFunc) elandev->process_frame,
-			&frames);
-	fpi_do_movement_estimation(&assembling_ctx, frames,
-				   elandev->num_frames);
-	img = fpi_assemble_frames(&assembling_ctx, frames, elandev->num_frames);
+	g_slist_foreach(raw_frames, (GFunc) elandev->process_frame, &frames);
+	fpi_do_movement_estimation(&assembling_ctx, frames, num_frames);
+	img = fpi_assemble_frames(&assembling_ctx, frames, num_frames);
 
 	img->flags |= FP_IMG_PARTIAL;
 	fpi_imgdev_image_captured(dev, img);
@@ -383,6 +382,12 @@ static void elan_cmd_read(fpi_ssm *ssm, struct fp_img_dev *dev)
 		return;
 	}
 
+	if (elandev->dev_type == ELAN_0C42) {
+		/* ELAN_0C42 sends an extra byte in one byte responses */
+		if (elandev->cmd->response_len == 1)
+			response_len = 2;
+	}
+
 	if (elandev->cmd->cmd == get_image_cmd.cmd)
 		/* raw data has 2-byte "pixels" and the frame is vertical */
 		response_len =
@@ -419,7 +424,8 @@ elan_run_cmd(fpi_ssm               *ssm,
 		elandev->cmd_timeout = cmd_timeout;
 
 	if (cmd->devices != ELAN_ALL_DEV && !(cmd->devices & elandev->dev_type)) {
-		fp_dbg("skipping for this device");
+		fp_dbg("skipping command 0x%x 0x%x for this device (for devices 0x%x but device is 0x%x)",
+		       cmd->cmd[0], cmd->cmd[1], cmd->devices, elandev->dev_type);
 		elan_cmd_done(ssm);
 		return;
 	}
@@ -597,6 +603,14 @@ static int elan_need_calibration(struct elan_dev *elandev)
 
 	g_assert(frame_size != 0);
 
+	if (elandev->dev_type == ELAN_0C42) {
+		if (calib_mean > 5500 ||
+		    calib_mean < 2500) {
+			fp_dbg("Forcing needed recalibration");
+			return 1;
+		}
+	}
+
 	for (int i = 0; i < frame_size; i++)
 		bg_mean += elandev->background[i];
 	bg_mean /= frame_size;
@@ -621,6 +635,14 @@ enum calibrate_states {
 	CALIBRATE_NUM_STATES,
 };
 
+static gboolean elan_supports_calibration(struct elan_dev *elandev)
+{
+	if (elandev->dev_type == ELAN_0C42)
+		return TRUE;
+
+	return elandev->fw_ver >= ELAN_MIN_CALIBRATION_FW;
+}
+
 static void calibrate_run_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 {
 	struct fp_img_dev *dev = user_data;
@@ -634,7 +656,7 @@ static void calibrate_run_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_da
 		break;
 	case CALIBRATE_SAVE_BACKGROUND:
 		elan_save_background(elandev);
-		if (elandev->fw_ver < ELAN_MIN_CALIBRATION_FW) {
+		if (!elan_supports_calibration(elandev)) {
 			fp_dbg("FW does not support calibration");
 			fpi_ssm_mark_completed(ssm);
 		} else
@@ -755,6 +777,14 @@ static void activate_run_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_dat
 			elandev->frame_height = elandev->raw_frame_height =
 			    elandev->last_read[0];
 		}
+		/* Work-around sensors returning the sizes as zero-based index
+		 * rather than the number of pixels. */
+		if ((elandev->frame_width % 2 == 1) &&
+		    (elandev->frame_height % 2 == 1)) {
+			elandev->frame_width++;
+			elandev->frame_height++;
+			elandev->raw_frame_height = elandev->frame_height;
+		}
 		if (elandev->frame_height > ELAN_MAX_FRAME_HEIGHT)
 			elandev->frame_height = ELAN_MAX_FRAME_HEIGHT;
 		fp_dbg("sensor dimensions, WxH: %dx%d", elandev->frame_width,
@@ -844,7 +874,7 @@ static void dev_deinit(struct fp_img_dev *dev)
 	fpi_imgdev_close_complete(dev);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	G_DEBUG_HERE();
 	elan_activate(dev);
diff --git a/libfprint/drivers/elan.h b/libfprint/drivers/elan.h
index 853f31de..c5f0f191 100644
--- a/libfprint/drivers/elan.h
+++ b/libfprint/drivers/elan.h
@@ -31,6 +31,7 @@
 /* devices with quirks */
 #define ELAN_0907 (1 << 0)
 #define ELAN_0C03 (1 << 1)
+#define ELAN_0C42 (1 << 2)
 
 /* devices which don't require frame rotation before assembling */
 #define ELAN_NOT_ROTATED ELAN_0C03
@@ -55,7 +56,7 @@
 
 /* number of frames to drop at the end of capture because frames captured
  * while the finger is being lifted can be bad */
-#define ELAN_SKIP_LAST_FRAMES 1
+#define ELAN_SKIP_LAST_FRAMES 2
 
 #define ELAN_CMD_LEN 0x2
 #define ELAN_EP_CMD_OUT (0x1 | LIBUSB_ENDPOINT_OUT)
@@ -207,6 +208,7 @@ static const struct usb_id elan_id_table[] = {
 	{.vendor = ELAN_VEND_ID,.product = 0x0c31,.driver_data = ELAN_ALL_DEV},
 	{.vendor = ELAN_VEND_ID,.product = 0x0c32,.driver_data = ELAN_ALL_DEV},
 	{.vendor = ELAN_VEND_ID,.product = 0x0c33,.driver_data = ELAN_ALL_DEV},
+	{.vendor = ELAN_VEND_ID,.product = 0x0c42,.driver_data = ELAN_0C42},
 	{0, 0, 0,},
 };
 
diff --git a/libfprint/drivers/etes603.c b/libfprint/drivers/etes603.c
index 97b6913b..f82fb05f 100644
--- a/libfprint/drivers/etes603.c
+++ b/libfprint/drivers/etes603.c
@@ -1316,7 +1316,7 @@ static void m_init_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 		fpi_ssm_next_state(ssm);
 		break;
 	case INIT_SENSOR_REQ:
-		/* In captured traffic, those are splitted. */
+		/* In captured traffic, those are split. */
 		msg_set_regs(dev, 18, REG_MODE_CONTROL, REG_MODE_SLEEP,
 			REG_50, 0x0F, REG_GAIN, 0x04, REG_VRT, 0x08,
 			REG_VRB, 0x0D, REG_VCO_CONTROL, REG_VCO_RT,
@@ -1390,19 +1390,13 @@ static void m_init_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 	fpi_ssm_free(ssm);
 }
 
-static int dev_activate(struct fp_img_dev *idev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *idev)
 {
 	struct etes603_dev *dev = FP_INSTANCE_DATA(FP_DEV(idev));
 	fpi_ssm *ssm;
 
 	g_assert(dev);
 
-	if (state != IMGDEV_STATE_AWAIT_FINGER_ON) {
-		fp_err("The driver is in an unexpected state: %d.", state);
-		fpi_imgdev_activate_complete(idev, 1);
-		return -1;
-	}
-
 	/* Reset info and data */
 	dev->is_active = TRUE;
 
@@ -1430,8 +1424,9 @@ static void dev_deactivate(struct fp_img_dev *idev)
 	/* this can be called even if still activated. */
 	if (dev->is_active == TRUE) {
 		dev->is_active = FALSE;
-		m_exit_start(idev);
 	}
+
+	m_exit_start(idev);
 }
 
 static int dev_open(struct fp_img_dev *idev, unsigned long driver_data)
diff --git a/libfprint/drivers/fdu2000.c b/libfprint/drivers/fdu2000.c
deleted file mode 100644
index 44b993dc..00000000
--- a/libfprint/drivers/fdu2000.c
+++ /dev/null
@@ -1,318 +0,0 @@
-/*
- * Secugen FDU2000 driver for libfprint
- * Copyright (C) 2007 Gustavo Chain <g@0xff.cl>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#define FP_COMPONENT "fdu2000"
-
-#include "drivers_api.h"
-
-#ifndef HAVE_MEMMEM
-gpointer
-memmem(const gpointer haystack, size_t haystack_len, const gpointer needle, size_t needle_len) {
-	const gchar *begin;
-	const char *const last_possible = (const char *) haystack + haystack_len - needle_len;
-
-	/* The first occurrence of the empty string is deemed to occur at 
-	 * the beginning of the string. */
-	if (needle_len == 0)
-		return (void *) haystack;
-	
-	/* Sanity check, otherwise the loop might search through the whole
-	 * memory.  */
-	if (haystack_len < needle_len)
-		return NULL;
-	
-	for (begin = (const char *) haystack; begin <= last_possible; ++begin)
-		if (begin[0] == ((const char *) needle)[0] &&
-			!memcmp((const void *) &begin[1],
-				(const void *) ((const char *) needle + 1),
-				needle_len - 1))
-			return (void *) begin;
-	
-	return NULL;
-}
-#endif	/* HAVE_MEMMEM */
-
-#define EP_IMAGE	( 0x02 | LIBUSB_ENDPOINT_IN )
-#define EP_REPLY	( 0x01 | LIBUSB_ENDPOINT_IN )
-#define EP_CMD		( 0x01 | LIBUSB_ENDPOINT_OUT )
-#define BULK_TIMEOUT	200
-
-/* fdu_req[] index */
-typedef enum {
-	CAPTURE_READY,
-	CAPTURE_READ,
-	CAPTURE_END,
-	LED_OFF,
-	LED_ON
-} req_index;
-
-
-#define CMD_LEN 2
-#define ACK_LEN 8
-static const struct fdu2000_req {
-	const gchar cmd[CMD_LEN];	// Command to send
-	const gchar ack[ACK_LEN];	// Expected ACK
-	const guint ack_len;	// ACK has variable length
-} fdu_req[] = {
-	/* Capture */
-	{
-		.cmd = { 0x00, 0x04 },
-		.ack = { 0x00, 0x04, 0x01, 0x01 },
-		.ack_len = 4
-	},
-	
-	{
-		.cmd = { 0x00, 0x01 },
-		.ack = { 0x00, 0x01, 0x01, 0x01 },
-		.ack_len = 4
-	},
-
-	{
-		.cmd = { 0x00, 0x05 },
-		.ack = { 0x00, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 },
-		.ack_len = 8
-	},
-
-	/* Led */
-	{
-		.cmd = { 0x05, 0x00 },
-		.ack = {},
-		.ack_len = 0
-	},
-
-	{
-		.cmd = { 0x05, 0x01 },
-		.ack = {},
-		.ack_len = 0
-	}
-};
-
-/*
- * Write a command and verify reponse
- */
-static gint
-bulk_write_safe(libusb_dev_handle *dev, req_index rIndex) {
-
-	gchar reponse[ACK_LEN];
-	gint r;
-	gchar *cmd = (gchar *)fdu_req[rIndex].cmd;
-	gchar *ack = (gchar *)fdu_req[rIndex].ack;
-	gint ack_len = fdu_req[rIndex].ack_len;
-	struct libusb_bulk_transfer wrmsg = {
-		.endpoint = EP_CMD,
-		.data = cmd,
-		.length = sizeof(cmd),
-	};
-	struct libusb_bulk_transfer readmsg = {
-		.endpoint = EP_REPLY,
-		.data = reponse,
-		.length = sizeof(reponse),
-	};
-	int trf;
-
-	r = libusb_bulk_transfer(dev, &wrmsg, &trf, BULK_TIMEOUT);
-	if (r < 0)
-		return r;
-
-	if (ack_len == 0)
-		return 0;
-
-	/* Check reply from FP */
-	r = libusb_bulk_transfer(dev, &readmsg, &trf, BULK_TIMEOUT);
-	if (r < 0)
-		return r;
-
-	if (!strncmp(ack, reponse, ack_len))
-		return 0;
-	
-	fp_err("Expected different ACK from dev");
-	return 1;	/* Error */
-}
-
-static gint
-capture(struct fp_img_dev *dev, gboolean unconditional,
-	struct fp_img **ret)
-{
-#define RAW_IMAGE_WIDTH		398
-#define RAW_IMAGE_HEIGTH	301
-#define RAW_IMAGE_SIZE		(RAW_IMAGE_WIDTH * RAW_IMAGE_HEIGTH)
-
-	struct fp_img *img = NULL;
-	int bytes, r;
-	const gchar SOF[] = { 0x0f, 0x0f, 0x0f, 0x0f, 0x00, 0x00, 0x0c, 0x07 };  // Start of frame
-	const gchar SOL[] = { 0x0f, 0x0f, 0x0f, 0x0f, 0x00, 0x00, 0x0b, 0x06 };  // Start of line + { L L } (L: Line num) (8 nibbles)
-	gchar *buffer = g_malloc0(RAW_IMAGE_SIZE * 6);
-	gchar *image;
-	gchar *p;
-	guint offset;
-	struct libusb_bulk_transfer msg = {
-		.endpoint = EP_IMAGE,
-		.data = buffer,
-		.length = RAW_IMAGE_SIZE * 6,
-	};
-
-	image  = g_malloc0(RAW_IMAGE_SIZE);
-
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), LED_ON))) {
-		fp_err("Command: LED_ON");
-		goto out;
-	}
-	
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), CAPTURE_READY))) {
-		fp_err("Command: CAPTURE_READY");
-		goto out;
-	}
-
-read:	
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), CAPTURE_READ))) {
-		fp_err("Command: CAPTURE_READ");
-		goto out;
-	}
-
-	/* Now we are ready to read from dev */
-
-	r = libusb_bulk_transfer(fpi_dev_get_usb_dev(FP_DEV(dev)), &msg, &bytes, BULK_TIMEOUT * 10);
-	if (r < 0 || bytes < 1)
-		goto read;
-
-	/*
-	 * Find SOF (start of line)
-	 */
-	p = memmem(buffer, RAW_IMAGE_SIZE * 6,
-			(const gpointer)SOF, sizeof SOF);
-	fp_dbg("Read %d byte/s from dev", bytes);
-	if (!p)
-		goto out;
-
-	p += sizeof SOF;
-
-	int i = 0;
-	bytes = 0;
-	while(p) {
-		if ( i >= RAW_IMAGE_HEIGTH )
-			break;
-
-		offset = p - buffer;
-		p = memmem(p, (RAW_IMAGE_SIZE * 6) - (offset),
-				(const gpointer)SOL, sizeof SOL);
-		if (p) {
-			p += sizeof SOL + 4;
-			int j;
-			for (j = 0; j < RAW_IMAGE_WIDTH; j++) {
-				/*
-				 * Convert from 4 to 8 bits
-				 * The SECUGEN-FDU2000 has 4 lines of data, so we need to join 2 bytes into 1
-				 */
-				*(image + bytes + j)  = *(p + (j * 2) + 0) << 4 & 0xf0;
-				*(image + bytes + j) |= *(p + (j * 2) + 1) & 0x0f;
-			}
-			p += RAW_IMAGE_WIDTH * 2;
-			bytes += RAW_IMAGE_WIDTH;
-			i++;
-		}
-	}
-
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), CAPTURE_END))) {
-		fp_err("Command: CAPTURE_END");
-		goto out;
-	}
-
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), LED_OFF))) {
-		fp_err("Command: LED_OFF");
-		goto out;
-	}
-
-	img = fpi_img_new_for_imgdev(dev);
-	memcpy(img->data, image, RAW_IMAGE_SIZE);
-	img->flags = FP_IMG_COLORS_INVERTED | FP_IMG_V_FLIPPED | FP_IMG_H_FLIPPED;
-	*ret = img;
-
-out:
-	g_free(buffer);
-	g_free(image);
-
-	return r;
-}
-
-static
-gint dev_init(struct fp_img_dev *dev, unsigned long driver_data)
-{
-	gint r;
-	//if ( (r = usb_set_configuration(fpi_dev_get_usb_dev(FP_DEV(dev)), 1)) < 0 )
-	//	goto out;
-
-	if ( (r = libusb_claim_interface(fpi_dev_get_usb_dev(FP_DEV(dev)), 0)) < 0 ) {
-		fp_err("could not claim interface 0: %s", libusb_error_name(r));
-		return r;
-	}
-
-	//if ( (r = usb_set_altinterface(fpi_dev_get_usb_dev(FP_DEV(dev)), 1)) < 0 )
-	//	goto out;
-
-	//if ( (r = usb_clear_halt(fpi_dev_get_usb_dev(FP_DEV(dev)), EP_CMD)) < 0 )
-	//	goto out;
-
-	/* Make sure sensor mode is not capture_{ready|read} */
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), CAPTURE_END))) {
-		fp_err("Command: CAPTURE_END");
-		goto out;
-	}
-
-	if ((r = bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), LED_OFF))) {
-		fp_err("Command: LED_OFF");
-		goto out;
-	}
-
-	return 0;
-
-out:
-	fp_err("could not init dev");
-	return r;
-}
-
-static
-void dev_exit(struct fp_img_dev *dev)
-{
-	if (bulk_write_safe(fpi_dev_get_usb_dev(FP_DEV(dev)), CAPTURE_END))
-		fp_err("Command: CAPTURE_END");
-
-	libusb_release_interface(fpi_dev_get_usb_dev(FP_DEV(dev)), 0);
-}
-
-static const struct usb_id id_table[] = {
-	{ .vendor = 0x1162, .product = 0x0300 },
-	{ 0, 0, 0, },
-};
-
-struct fp_img_driver fdu2000_driver = {
-	.driver = {
-		.id = FDU2000_ID,
-		.name = FP_COMPONENT,
-		.full_name = "Secugen FDU 2000",
-		.id_table = id_table,
-		.scan_type = FP_SCAN_TYPE_PRESS,
-	},
-	.img_height = RAW_IMAGE_HEIGTH,
-	.img_width = RAW_IMAGE_WIDTH,
-	.bz3_threshold = 23,
-
-	.init = dev_init,
-	.exit = dev_exit,
-	.capture = capture,
-};
diff --git a/libfprint/drivers/upeksonly.c b/libfprint/drivers/upeksonly.c
index 99c5ffae..69a79e69 100644
--- a/libfprint/drivers/upeksonly.c
+++ b/libfprint/drivers/upeksonly.c
@@ -136,7 +136,7 @@ static unsigned char upeksonly_get_pixel(struct fpi_line_asmbl_ctx *ctx,
 	unsigned char *buf;
 	unsigned offset;
 
-	/* The scans from this device are rolled right by two colums */
+	/* The scans from this device are rolled right by two columns */
 	if (x < ctx->line_width - 2)
 		offset = x + 2;
 	else if ((x > ctx->line_width - 2) && (x < ctx->line_width))
@@ -296,12 +296,12 @@ static void row_complete(struct fp_img_dev *dev)
 			sdev->num_blank = 0;
 		} else {
 			sdev->num_blank++;
-			/* Don't consider the scan complete unless theres at least
+			/* Don't consider the scan complete unless there's at least
 			 * MIN_ROWS recorded or very long blank read occurred.
 			 *
 			 * Typical problem spot: one brief touch before starting the
 			 * actual scan. Happens most commonly if scan is started
-			 * from before the first joint resulting in a gap after the inital touch.
+			 * from before the first joint resulting in a gap after the initial touch.
 			 */
 			if (sdev->num_blank > FINGER_REMOVED_THRESHOLD) {
 				sdev->finger_state = FINGER_REMOVED;
@@ -1268,7 +1268,7 @@ static void initsm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 	fpi_ssm_start(sdev->loopsm, loopsm_complete);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct sonly_dev *sdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm = NULL;
diff --git a/libfprint/drivers/upektc.c b/libfprint/drivers/upektc.c
index 0042833e..00d9c553 100644
--- a/libfprint/drivers/upektc.c
+++ b/libfprint/drivers/upektc.c
@@ -377,7 +377,7 @@ static void start_capture(struct fp_img_dev *dev)
 	fpi_ssm_start(ssm, capture_sm_complete);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct upektc_dev *upekdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), activate_run_state,
diff --git a/libfprint/drivers/upektc_img.c b/libfprint/drivers/upektc_img.c
index d749ac51..988793dc 100644
--- a/libfprint/drivers/upektc_img.c
+++ b/libfprint/drivers/upektc_img.c
@@ -287,7 +287,7 @@ static void capture_read_data_cb(struct libusb_transfer *transfer)
 				fpi_ssm_mark_completed(ssm);
 				break;
 			default:
-				fp_err("Uknown response!\n");
+				fp_err("Unknown response!\n");
 				fpi_ssm_mark_failed(ssm, -EIO);
 				break;
 		}
@@ -567,7 +567,7 @@ static void activate_sm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_d
 		start_capture(dev);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct upektc_img_dev *upekdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), activate_run_state,
diff --git a/libfprint/drivers/uru4000.c b/libfprint/drivers/uru4000.c
index 7830c562..79c48c5b 100644
--- a/libfprint/drivers/uru4000.c
+++ b/libfprint/drivers/uru4000.c
@@ -668,7 +668,7 @@ static uint32_t do_decode(uint8_t *data, int num_bytes, uint32_t key)
 		data[i] = data[i+1] ^ xorbyte;
 	}
 
-	/* the final byte is implictly zero */
+	/* the final byte is implicitly zero */
 	data[i] = 0;
 	return update_key(key);
 }
@@ -710,7 +710,7 @@ static void imaging_run_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data
 	uint32_t key;
 	uint8_t flags, num_lines;
 	int i, r, to, dev2;
-	char buf[5];
+	unsigned char buf[5];
 
 	switch (fpi_ssm_get_cur_state(ssm)) {
 	case IMAGING_CAPTURE:
@@ -1161,20 +1161,10 @@ static void activate_initsm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *us
 	int r = fpi_ssm_get_error(ssm);
 	fpi_ssm_free(ssm);
 
-	if (r) {
-		fpi_imgdev_activate_complete(dev, r);
-		return;
-	}
-
-	r = execute_state_change(dev);
 	fpi_imgdev_activate_complete(dev, r);
 }
 
-/* FIXME: having state parameter here is kinda useless, will we ever
- * see a scenario where the parameter is useful so early on in the activation
- * process? asynchronity means that it'll only be used in a later function
- * call. */
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct uru4k_dev *urudev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm;
@@ -1185,7 +1175,6 @@ static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
 		return r;
 
 	urudev->scanpwr_irq_timeouts = 0;
-	urudev->activate_state = state;
 	ssm = fpi_ssm_new(FP_DEV(dev), init_run_state, INIT_NUM_STATES, dev);
 	fpi_ssm_start(ssm, activate_initsm_complete);
 	return 0;
@@ -1340,6 +1329,9 @@ static int dev_init(struct fp_img_dev *dev, unsigned long driver_data)
 		goto out;
 	}
 
+	/* Disable loading p11-kit's user configuration */
+	g_setenv ("P11_KIT_NO_USER_CONFIG", "1", TRUE);
+
 	/* Initialise NSS early */
 	rv = NSS_NoDB_Init(".");
 	if (rv != SECSuccess) {
diff --git a/libfprint/drivers/vcom5s.c b/libfprint/drivers/vcom5s.c
index 4ed71f69..b0c6c452 100644
--- a/libfprint/drivers/vcom5s.c
+++ b/libfprint/drivers/vcom5s.c
@@ -302,7 +302,7 @@ static void loopsm_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 		fpi_imgdev_deactivate_complete(dev);
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct v5s_dev *vdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm = fpi_ssm_new(FP_DEV(dev), loop_run_state,
diff --git a/libfprint/drivers/vfs0050.c b/libfprint/drivers/vfs0050.c
index a437df4f..b2f8395e 100644
--- a/libfprint/drivers/vfs0050.c
+++ b/libfprint/drivers/vfs0050.c
@@ -577,7 +577,7 @@ static void activate_ssm(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 			vdev->need_report = 0;
 		}
 
-		/* Asyncronously enquire an interrupt */
+		/* Asynchronously enquire an interrupt */
 		vdev->transfer = fpi_usb_alloc();
 		vdev->transfer->flags |= LIBUSB_TRANSFER_FREE_TRANSFER;
 		libusb_fill_interrupt_transfer(vdev->transfer, usb_dev, 0x83,
@@ -684,7 +684,7 @@ static void dev_activate_callback(fpi_ssm *ssm, struct fp_dev *_dev, void *user_
 }
 
 /* Activate device */
-static int dev_activate(struct fp_img_dev *idev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *idev)
 {
 	struct vfs_dev_t *vdev = FP_INSTANCE_DATA(FP_DEV(idev));
 
diff --git a/libfprint/drivers/vfs101.c b/libfprint/drivers/vfs101.c
index 8faaa230..60f0a819 100644
--- a/libfprint/drivers/vfs101.c
+++ b/libfprint/drivers/vfs101.c
@@ -47,7 +47,7 @@
 /* Minimum image height */
 #define VFS_IMG_MIN_HEIGHT	200
 
-/* Scan level thresold */
+/* Scan level threshold */
 #define VFS_IMG_SLT_BEGIN		768
 #define VFS_IMG_SLT_END			64
 #define VFS_IMG_SLT_LINES		4
@@ -641,7 +641,7 @@ static int action_completed(struct fp_img_dev *dev)
 
 #define offset(x, y)	((x) + ((y) * VFS_FRAME_SIZE))
 
-/* Screen image to remove noise and find bottom line and height od image */
+/* Screen image to remove noise and find bottom line and height of image */
 static void img_screen(struct vfs101_dev *vdev)
 {
 	int y, x, count, top;
@@ -654,7 +654,7 @@ static void img_screen(struct vfs101_dev *vdev)
 
 	/* Image returned from sensor can contain many empty lines,
 	 * for remove these lines compare byte 282-283 (scan level information)
-	 * with two differents threshold, one for the begin of finger image and
+	 * with two different thresholds, one for the begin of finger image and
 	 * one for the end. To increase stability of the code use a counter
 	 * of lines that satisfy the threshold.
 	 */
@@ -700,7 +700,7 @@ static void img_screen(struct vfs101_dev *vdev)
 
 	vdev->height = top - vdev->bottom + 1;
 
-	/* Checkk max height */
+	/* Check max height */
 	if (vdev->height > VFS_IMG_MAX_HEIGHT)
 		vdev->height = VFS_IMG_MAX_HEIGHT;
 
@@ -1178,7 +1178,7 @@ static void m_init_state(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 	switch (fpi_ssm_get_cur_state(ssm))
 	{
 	case M_INIT_0_RECV_DIRTY:
-		/* Recv eventualy dirty data */
+		/* Recv eventually dirty data */
 		vdev->ignore_error = TRUE;
 		async_recv(ssm, dev);
 		break;
@@ -1424,7 +1424,7 @@ static void m_init_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 }
 
 /* Activate device */
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct vfs101_dev *vdev = FP_INSTANCE_DATA(FP_DEV(dev));
 	fpi_ssm *ssm;
@@ -1463,7 +1463,7 @@ static void dev_deactivate(struct fp_img_dev *dev)
 	/* Reset active state */
 	vdev->active = FALSE;
 
-	/* Handle eventualy existing events */
+	/* Handle eventually existing events */
 	while (vdev->transfer)
 		fp_handle_events();
 
diff --git a/libfprint/drivers/vfs301.c b/libfprint/drivers/vfs301.c
index 4116e71e..94837de0 100644
--- a/libfprint/drivers/vfs301.c
+++ b/libfprint/drivers/vfs301.c
@@ -191,7 +191,7 @@ static void m_init_complete(fpi_ssm *ssm, struct fp_dev *_dev, void *user_data)
 }
 
 /* Activate device */
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	fpi_ssm *ssm;
 
diff --git a/libfprint/drivers/vfs301_proto.h b/libfprint/drivers/vfs301_proto.h
index daa629aa..2ae587a1 100644
--- a/libfprint/drivers/vfs301_proto.h
+++ b/libfprint/drivers/vfs301_proto.h
@@ -109,7 +109,7 @@ typedef struct {
 
 	unsigned char scan[VFS301_FP_WIDTH];
 
-	/* A offseted, stretched, inverted copy of scan... probably could
+	/* A offsetted, stretched, inverted copy of scan... probably could
 	 * serve finger motion speed detection?
 	 * Seems to be subdivided to some 10B + 53B + 1B blocks */
 	unsigned char mirror[64];
diff --git a/libfprint/drivers/vfs301_proto_fragments.h b/libfprint/drivers/vfs301_proto_fragments.h
index c000441c..39441a13 100644
--- a/libfprint/drivers/vfs301_proto_fragments.h
+++ b/libfprint/drivers/vfs301_proto_fragments.h
@@ -1147,7 +1147,7 @@ static const unsigned char vfs301_24[] = { /* 119 B */
  *
  * The contents of PACKET() inside this blob seems to be some kind
  * of a micro-program, which specifies which columns contain what. LE seems
- * to be used also here. Not neccessarily is 1 output column described
+ * to be used also here. Not necessarily is 1 output column described
  * by 1 operation. For example the vfs301_line_t::sum section seems
  * to perform 2 operations for each column - probably some kind of diff between
  * input lines?
diff --git a/libfprint/drivers/vfs5011.c b/libfprint/drivers/vfs5011.c
index 2fcb822a..c7121f9d 100644
--- a/libfprint/drivers/vfs5011.c
+++ b/libfprint/drivers/vfs5011.c
@@ -371,7 +371,7 @@ static int process_chunk(struct vfs5011_data *data, int transferred)
 				VFS5011_IMAGE_WIDTH) >= DIFFERENCE_THRESHOLD)) {
 			data->lastline = g_malloc(VFS5011_LINE_SIZE);
 			data->rows = g_slist_prepend(data->rows, data->lastline);
-			g_memmove(data->lastline, linebuf, VFS5011_LINE_SIZE);
+			memmove(data->lastline, linebuf, VFS5011_LINE_SIZE);
 			data->lines_recorded++;
 			if (data->lines_recorded >= data->max_lines_recorded) {
 				fp_dbg("process_chunk: recorded %d lines, finishing",
@@ -405,7 +405,7 @@ submit_image(fpi_ssm             *ssm,
 	g_slist_free_full(data->rows, g_free);
 	data->rows = NULL;
 
-	fp_dbg("Image captured, commiting");
+	fp_dbg("Image captured, committing");
 
 	fpi_imgdev_image_captured(dev, img);
 }
@@ -846,7 +846,7 @@ static void start_scan(struct fp_img_dev *dev)
 	fp_dbg("ssm done, getting out");
 }
 
-static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *dev)
 {
 	struct vfs5011_data *data;
 
@@ -879,6 +879,7 @@ static void dev_deactivate(struct fp_img_dev *dev)
 static const struct usb_id id_table[] = {
 	{ .vendor = 0x138a, .product = 0x0010 /* Validity device from some Toshiba laptops */ },
 	{ .vendor = 0x138a, .product = 0x0011 /* vfs5011 */ },
+	{ .vendor = 0x138a, .product = 0x0015 /* Validity device from Lenovo Preferred Pro USB Fingerprint Keyboard KUF1256 */ },
 	{ .vendor = 0x138a, .product = 0x0017 /* Validity device from Lenovo T440 laptops */ },
 	{ .vendor = 0x138a, .product = 0x0018 /* one more Validity device */ },
 	{ 0, 0, 0, },
diff --git a/libfprint/fpi-assembling.c b/libfprint/fpi-assembling.c
index e33dafe5..65fad4d7 100644
--- a/libfprint/fpi-assembling.c
+++ b/libfprint/fpi-assembling.c
@@ -365,7 +365,7 @@ static void median_filter(int *data, int size, int filtersize)
 			i1 = 0;
 		if (i2 >= size)
 			i2 = size-1;
-		g_memmove(sortbuf, data+i1, (i2-i1+1)*sizeof(int));
+		memmove(sortbuf, data+i1, (i2-i1+1)*sizeof(int));
 		g_qsort_with_data(sortbuf, i2-i1+1, sizeof(int), cmpint, NULL);
 		result[i] = sortbuf[(i2-i1+1)/2];
 	}
@@ -480,7 +480,7 @@ out:
 	img->height = line_ind;
 	img->width = ctx->line_width;
 	img->flags = FP_IMG_V_FLIPPED;
-	g_memmove(img->data, output, ctx->line_width * line_ind);
+	memmove(img->data, output, ctx->line_width * line_ind);
 	g_free(offsets);
 	g_free(output);
 	return img;
diff --git a/libfprint/fpi-async.c b/libfprint/fpi-async.c
index ddf5230b..6339c9ca 100644
--- a/libfprint/fpi-async.c
+++ b/libfprint/fpi-async.c
@@ -387,9 +387,21 @@ API_EXPORTED int fp_async_verify_stop(struct fp_dev *dev,
 
 	g_return_val_if_fail(dev != NULL, -ENODEV);
 
+	G_DEBUG_HERE();
+
+	if (dev->state == DEV_STATE_VERIFY_STOPPING) {
+		fp_dbg ("Already stopping verification, returning -EINPROGRESS");
+		return -EINPROGRESS;
+	}
+
+	if (dev->state == DEV_STATE_INITIALIZED) {
+		if (callback)
+			callback(dev, user_data);
+		return 0;
+	}
+
 	drv = dev->drv;
 
-	G_DEBUG_HERE();
 	BUG_ON(dev->state != DEV_STATE_ERROR
 		&& dev->state != DEV_STATE_VERIFYING
 		&& dev->state != DEV_STATE_VERIFY_DONE);
@@ -511,9 +523,21 @@ API_EXPORTED int fp_async_identify_stop(struct fp_dev *dev,
 
 	g_return_val_if_fail(dev != NULL, -ENODEV);
 
+	G_DEBUG_HERE();
+
+	if (dev->state == DEV_STATE_IDENTIFY_STOPPING) {
+		fp_dbg ("Already stopping identification, returning -EINPROGRESS");
+		return -EINPROGRESS;
+	}
+
+	if (dev->state == DEV_STATE_INITIALIZED) {
+		if (callback)
+			callback(dev, user_data);
+		return 0;
+	}
+
 	drv = dev->drv;
 
-	G_DEBUG_HERE();
 	BUG_ON(dev->state != DEV_STATE_IDENTIFYING
 		&& dev->state != DEV_STATE_IDENTIFY_DONE);
 
diff --git a/libfprint/fpi-core.c b/libfprint/fpi-core.c
index 2b5d3c6f..6009c82d 100644
--- a/libfprint/fpi-core.c
+++ b/libfprint/fpi-core.c
@@ -270,10 +270,12 @@ static struct fp_dscv_dev *discover_dev(libusb_device *udev)
  * fp_discover_devs:
  *
  * Scans the system and returns a list of discovered devices. This is your
- * entry point into finding a fingerprint reader to operate.
+ * entry point into finding a fingerprint reader to operate. Note that %NULL
+ * is only returned on error. When there are no supported readers available,
+ * an empty list is returned instead.
  *
- * Returns: a nul-terminated list of discovered devices. Must be freed with
- * fp_dscv_devs_free() after use.
+ * Returns: a nul-terminated list of discovered devices or %NULL on error.
+ * Must be freed with fp_dscv_devs_free() after use.
  */
 API_EXPORTED struct fp_dscv_dev **fp_discover_devs(void)
 {
@@ -344,6 +346,8 @@ API_EXPORTED void fp_dscv_devs_free(struct fp_dscv_dev **devs)
  */
 API_EXPORTED struct fp_driver *fp_dscv_dev_get_driver(struct fp_dscv_dev *dev)
 {
+	g_return_val_if_fail(dev, NULL);
+
 	return dev->drv;
 }
 
@@ -358,6 +362,8 @@ API_EXPORTED struct fp_driver *fp_dscv_dev_get_driver(struct fp_dscv_dev *dev)
  */
 API_EXPORTED uint16_t fp_dscv_dev_get_driver_id(struct fp_dscv_dev *dev)
 {
+	g_return_val_if_fail(dev, 0);
+
 	return fp_driver_get_driver_id(fp_dscv_dev_get_driver(dev));
 }
 
@@ -371,6 +377,8 @@ API_EXPORTED uint16_t fp_dscv_dev_get_driver_id(struct fp_dscv_dev *dev)
  */
 API_EXPORTED uint32_t fp_dscv_dev_get_devtype(struct fp_dscv_dev *dev)
 {
+	g_return_val_if_fail(dev, 0);
+
 	return dev->devtype;
 }
 
@@ -400,6 +408,9 @@ enum fp_print_data_type fpi_driver_get_data_type(struct fp_driver *drv)
 API_EXPORTED int fp_dscv_dev_supports_print_data(struct fp_dscv_dev *dev,
 	struct fp_print_data *print)
 {
+	g_return_val_if_fail(dev, 0);
+	g_return_val_if_fail(print, 0);
+
 	return fpi_print_data_compatible(dev->drv->id, dev->devtype,
 		fpi_driver_get_data_type(dev->drv), print->driver_id, print->devtype,
 		print->type);
@@ -420,6 +431,9 @@ API_EXPORTED int fp_dscv_dev_supports_print_data(struct fp_dscv_dev *dev,
 API_EXPORTED int fp_dscv_dev_supports_dscv_print(struct fp_dscv_dev *dev,
 	struct fp_dscv_print *print)
 {
+	g_return_val_if_fail(dev, 0);
+	g_return_val_if_fail(print, 0);
+
 	return fpi_print_data_compatible(dev->drv->id, dev->devtype, 0,
 		print->driver_id, print->devtype, 0);
 }
@@ -443,6 +457,9 @@ API_EXPORTED struct fp_dscv_dev *fp_dscv_dev_for_print_data(struct fp_dscv_dev *
 	struct fp_dscv_dev *ddev;
 	int i;
 
+	g_return_val_if_fail(devs, NULL);
+	g_return_val_if_fail(print, NULL);
+
 	for (i = 0; (ddev = devs[i]); i++)
 		if (fp_dscv_dev_supports_print_data(ddev, print))
 			return ddev;
@@ -468,6 +485,9 @@ API_EXPORTED struct fp_dscv_dev *fp_dscv_dev_for_dscv_print(struct fp_dscv_dev *
 	struct fp_dscv_dev *ddev;
 	int i;
 
+	g_return_val_if_fail(devs, NULL);
+	g_return_val_if_fail(print, NULL);
+
 	for (i = 0; (ddev = devs[i]); i++) {
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
@@ -488,6 +508,8 @@ API_EXPORTED struct fp_dscv_dev *fp_dscv_dev_for_dscv_print(struct fp_dscv_dev *
  */
 API_EXPORTED struct fp_driver *fp_dev_get_driver(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, NULL);
+
 	return dev->drv;
 }
 
@@ -502,6 +524,8 @@ API_EXPORTED struct fp_driver *fp_dev_get_driver(struct fp_dev *dev)
  */
 API_EXPORTED int fp_dev_get_nr_enroll_stages(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, 0);
+
 	return dev->nr_enroll_stages;
 }
 
@@ -515,6 +539,8 @@ API_EXPORTED int fp_dev_get_nr_enroll_stages(struct fp_dev *dev)
  */
 API_EXPORTED uint32_t fp_dev_get_devtype(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, 0);
+
 	return dev->devtype;
 }
 
@@ -530,6 +556,9 @@ API_EXPORTED uint32_t fp_dev_get_devtype(struct fp_dev *dev)
 API_EXPORTED int fp_dev_supports_print_data(struct fp_dev *dev,
 	struct fp_print_data *data)
 {
+	g_return_val_if_fail(dev, 0);
+	g_return_val_if_fail(data, 0);
+
 	return fpi_print_data_compatible(dev->drv->id, dev->devtype,
 		fpi_driver_get_data_type(dev->drv), data->driver_id, data->devtype,
 		data->type);
@@ -550,6 +579,9 @@ API_EXPORTED int fp_dev_supports_print_data(struct fp_dev *dev,
 API_EXPORTED int fp_dev_supports_dscv_print(struct fp_dev *dev,
 	struct fp_dscv_print *print)
 {
+	g_return_val_if_fail(dev, 0);
+	g_return_val_if_fail(print, 0);
+
 	return fpi_print_data_compatible(dev->drv->id, dev->devtype,
 		0, print->driver_id, print->devtype, 0);
 }
@@ -564,6 +596,8 @@ API_EXPORTED int fp_dev_supports_dscv_print(struct fp_dev *dev,
  */
 API_EXPORTED const char *fp_driver_get_name(struct fp_driver *drv)
 {
+	g_return_val_if_fail(drv, NULL);
+
 	return drv->name;
 }
 
@@ -577,6 +611,8 @@ API_EXPORTED const char *fp_driver_get_name(struct fp_driver *drv)
  */
 API_EXPORTED const char *fp_driver_get_full_name(struct fp_driver *drv)
 {
+	g_return_val_if_fail(drv, NULL);
+
 	return drv->full_name;
 }
 
@@ -590,6 +626,8 @@ API_EXPORTED const char *fp_driver_get_full_name(struct fp_driver *drv)
  */
 API_EXPORTED uint16_t fp_driver_get_driver_id(struct fp_driver *drv)
 {
+	g_return_val_if_fail(drv, 0);
+
 	return drv->id;
 }
 
@@ -603,6 +641,8 @@ API_EXPORTED uint16_t fp_driver_get_driver_id(struct fp_driver *drv)
  */
 API_EXPORTED enum fp_scan_type fp_driver_get_scan_type(struct fp_driver *drv)
 {
+	g_return_val_if_fail(drv, FP_SCAN_TYPE_PRESS);
+
 	return drv->scan_type;
 }
 
@@ -621,6 +661,8 @@ API_EXPORTED enum fp_scan_type fp_driver_get_scan_type(struct fp_driver *drv)
  */
 API_EXPORTED int fp_driver_supports_imaging(struct fp_driver *drv)
 {
+	g_return_val_if_fail(drv, 0);
+
 	return drv->capture_start != NULL;
 }
 
@@ -639,6 +681,8 @@ API_EXPORTED int fp_driver_supports_imaging(struct fp_driver *drv)
  */
 API_EXPORTED int fp_dev_supports_imaging(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, 0);
+
 	return dev->drv->capture_start != NULL;
 }
 
@@ -654,6 +698,8 @@ API_EXPORTED int fp_dev_supports_imaging(struct fp_dev *dev)
  */
 API_EXPORTED int fp_dev_supports_identification(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, 0);
+
 	return dev->drv->identify_start != NULL;
 }
 
@@ -671,6 +717,8 @@ API_EXPORTED int fp_dev_supports_identification(struct fp_dev *dev)
  */
 API_EXPORTED int fp_dev_get_img_width(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, -1);
+
 	if (!dev->img_dev) {
 		fp_dbg("get image width for non-imaging device");
 		return -1;
@@ -693,6 +741,8 @@ API_EXPORTED int fp_dev_get_img_width(struct fp_dev *dev)
  */
 API_EXPORTED int fp_dev_get_img_height(struct fp_dev *dev)
 {
+	g_return_val_if_fail(dev, -1);
+
 	if (!dev->img_dev) {
 		fp_dbg("get image height for non-imaging device");
 		return -1;
diff --git a/libfprint/fpi-core.h b/libfprint/fpi-core.h
index a5a0a44d..d183f885 100644
--- a/libfprint/fpi-core.h
+++ b/libfprint/fpi-core.h
@@ -110,7 +110,7 @@ struct fp_img_driver {
 	/* Device operations */
 	int (*open)(struct fp_img_dev *dev, unsigned long driver_data);
 	void (*close)(struct fp_img_dev *dev);
-	int (*activate)(struct fp_img_dev *dev, enum fp_imgdev_state state);
+	int (*activate)(struct fp_img_dev *dev);
 	int (*change_state)(struct fp_img_dev *dev, enum fp_imgdev_state state);
 	void (*deactivate)(struct fp_img_dev *dev);
 };
diff --git a/libfprint/fpi-data.c b/libfprint/fpi-data.c
index 0ac0f987..c19142ac 100644
--- a/libfprint/fpi-data.c
+++ b/libfprint/fpi-data.c
@@ -56,12 +56,15 @@ struct fpi_print_data_item_fp2 {
  *
  * This page documents the various operations you can do with a stored print.
  * Note that by default, "stored prints" are not actually stored anywhere
- * except in RAM. For the simple scenarios, libfprint provides a simple API
- * for you to save and load the stored prints referring to a single user in
- * their home directory. For more advanced users, libfprint provides APIs for
- * you to convert print data to a byte string, and to reconstruct stored prints
+ * except in RAM. Storage needs to be handled by the API user by using the
+ * fp_print_data_get_data() and fp_print_data_from_data(). This API allows
+ * to convert print data into byte strings, and to reconstruct stored prints
  * from such data at a later point. You are welcome to store these byte strings
  * in any fashion that suits you.
+ *
+ * The provided API to store data on disk is deprecated and should not be
+ * used anymore. This API stored the prints in the current user's home
+ * directory.
  */
 
 /*
@@ -211,7 +214,7 @@ API_EXPORTED size_t fp_print_data_get_data(struct fp_print_data *data,
 		item = list_item->data;
 		out_item = (struct fpi_print_data_item_fp2 *)buf;
 		out_item->length = GUINT32_TO_LE(item->length);
-		/* FIXME: fp_print_data_item->data content is not endianess agnostic */
+		/* FIXME: fp_print_data_item->data content is not endianness agnostic */
 		memcpy(out_item->data, item->data, item->length);
 		buf += sizeof(*out_item);
 		buf += item->length;
@@ -233,7 +236,7 @@ static struct fp_print_data *fpi_print_data_from_fp1_data(unsigned char *buf,
 	data = print_data_new(GUINT16_FROM_LE(raw->driver_id),
 		GUINT32_FROM_LE(raw->devtype), raw->data_type);
 	item = fpi_print_data_item_new(print_data_len);
-	/* FIXME: fp_print_data->data content is not endianess agnostic */
+	/* FIXME: fp_print_data->data content is not endianness agnostic */
 	memcpy(item->data, raw->data, print_data_len);
 	data->prints = g_slist_prepend(data->prints, item);
 
@@ -269,7 +272,7 @@ static struct fp_print_data *fpi_print_data_from_fp2_data(unsigned char *buf,
 		total_data_len -= item_len;
 
 		item = fpi_print_data_item_new(item_len);
-		/* FIXME: fp_print_data->data content is not endianess agnostic */
+		/* FIXME: fp_print_data->data content is not endianness agnostic */
 		memcpy(item->data, raw_item->data, item_len);
 		data->prints = g_slist_prepend(data->prints, item);
 
@@ -366,6 +369,10 @@ static char *get_path_to_print(struct fp_dev *dev, enum fp_finger finger)
  * directory beneath the current user's home directory.
  *
  * Returns: 0 on success, non-zero on error.
+ *
+ * Deprecated: Data storage should be handled outside of libfprint.
+ * See <link linkend="libfprint-Stored-prints.description">stored prints description</link>
+ * for more information.
  */
 API_EXPORTED int fp_print_data_save(struct fp_print_data *data,
 	enum fp_finger finger)
@@ -478,6 +485,10 @@ static int load_from_file(char *path, struct fp_print_data **data)
  * obscure error conditions (e.g. corruption).
  *
  * Returns: 0 on success, non-zero on error
+ *
+ * Deprecated: Data storage should be handled outside of libfprint.
+ * See <link linkend="libfprint-Stored-prints.description">stored prints description</link>
+ * for more information.
  */
 API_EXPORTED int fp_print_data_load(struct fp_dev *dev,
 	enum fp_finger finger, struct fp_print_data **data)
@@ -513,6 +524,10 @@ API_EXPORTED int fp_print_data_load(struct fp_dev *dev,
  * Removes a stored print from disk previously saved with fp_print_data_save().
  *
  * Returns: 0 on success, negative on error
+ *
+ * Deprecated: Data storage should be handled outside of libfprint.
+ * See <link linkend="libfprint-Stored-prints.description">stored prints description</link>
+ * for more information.
  */
 API_EXPORTED int fp_print_data_delete(struct fp_dev *dev,
 	enum fp_finger finger)
diff --git a/libfprint/fpi-dev-img.c b/libfprint/fpi-dev-img.c
index 93f1f47e..b9d27831 100644
--- a/libfprint/fpi-dev-img.c
+++ b/libfprint/fpi-dev-img.c
@@ -485,9 +485,15 @@ void fpi_imgdev_activate_complete(struct fp_img_dev *imgdev, int status)
  */
 void fpi_imgdev_deactivate_complete(struct fp_img_dev *imgdev)
 {
+	enum fp_imgdev_action action;
+
 	G_DEBUG_HERE();
 
-	switch (imgdev->action) {
+	action = imgdev->action;
+	imgdev->action = IMG_ACTION_NONE;
+	imgdev->action_state = 0;
+
+	switch (action) {
 	case IMG_ACTION_ENROLL:
 		fpi_drvcb_enroll_stopped(FP_DEV(imgdev));
 		break;
@@ -504,9 +510,6 @@ void fpi_imgdev_deactivate_complete(struct fp_img_dev *imgdev)
 		fp_err("unhandled action %d", imgdev->action);
 		break;
 	}
-
-	imgdev->action = IMG_ACTION_NONE;
-	imgdev->action_state = 0;
 }
 
 int fpi_imgdev_get_img_width(struct fp_img_dev *imgdev)
@@ -533,14 +536,14 @@ int fpi_imgdev_get_img_height(struct fp_img_dev *imgdev)
 	return height;
 }
 
-static int dev_activate(struct fp_img_dev *imgdev, enum fp_imgdev_state state)
+static int dev_activate(struct fp_img_dev *imgdev)
 {
 	struct fp_driver *drv = FP_DEV(imgdev)->drv;
 	struct fp_img_driver *imgdrv = fpi_driver_to_img_driver(drv);
 
 	if (!imgdrv->activate)
 		return 0;
-	return imgdrv->activate(imgdev, state);
+	return imgdrv->activate(imgdev);
 }
 
 static void dev_deactivate(struct fp_img_dev *imgdev)
@@ -562,7 +565,7 @@ static int generic_acquire_start(struct fp_dev *dev, int action)
 	imgdev->action_state = IMG_ACQUIRE_STATE_ACTIVATING;
 	imgdev->enroll_stage = 0;
 
-	r = dev_activate(imgdev, IMGDEV_STATE_AWAIT_FINGER_ON);
+	r = dev_activate(imgdev);
 	if (r < 0)
 		fp_err("activation failed with error %d", r);
 
diff --git a/libfprint/fpi-img.c b/libfprint/fpi-img.c
index f5ebea7f..c7f44c24 100644
--- a/libfprint/fpi-img.c
+++ b/libfprint/fpi-img.c
@@ -405,7 +405,7 @@ int fpi_img_to_print_data(struct fp_img_dev *imgdev, struct fp_img *img,
 		}
 	}
 
-	/* FIXME: space is wasted if we dont hit the max minutiae count. would
+	/* FIXME: space is wasted if we don't hit the max minutiae count. would
 	 * be good to make this dynamic. */
 	print = fpi_print_data_new(FP_DEV(imgdev));
 	item = fpi_print_data_item_new(sizeof(struct xyt_struct));
diff --git a/libfprint/fpi-poll.c b/libfprint/fpi-poll.c
index af0c4bee..3f2c898f 100644
--- a/libfprint/fpi-poll.c
+++ b/libfprint/fpi-poll.c
@@ -91,8 +91,6 @@ struct fpi_timeout {
 	char *name;
 };
 
-static gboolean fpi_poll_is_setup(void);
-
 static int timeout_sort_fn(gconstpointer _a, gconstpointer _b)
 {
 	fpi_timeout *a = (fpi_timeout *) _a;
@@ -167,7 +165,6 @@ fpi_timeout *fpi_timeout_add(unsigned int    msec,
 	int r;
 
 	g_return_val_if_fail (dev != NULL, NULL);
-	g_return_val_if_fail (fpi_poll_is_setup(), NULL);
 
 	fp_dbg("in %dms", msec);
 
@@ -210,26 +207,6 @@ void fpi_timeout_cancel(fpi_timeout *timeout)
 	fpi_timeout_free(timeout);
 }
 
-void
-fpi_timeout_cancel_for_dev(struct fp_dev *dev)
-{
-	GSList *l;
-
-	g_return_if_fail (dev != NULL);
-
-	l = active_timers;
-	while (l) {
-		struct fpi_timeout *timeout = l->data;
-		GSList *current = l;
-
-		l = l->next;
-		if (timeout->dev == dev) {
-			fpi_timeout_free (timeout);
-			active_timers = g_slist_delete_link (active_timers, current);
-		}
-	}
-}
-
 /* get the expiry time and optionally the timeout structure for the next
  * timeout. returns 0 if there are no expired timers, or 1 if the
  * timeval/timeout output parameters were populated. if the returned timeval
@@ -487,12 +464,6 @@ void fpi_poll_exit(void)
 	libusb_set_pollfd_notifiers(fpi_usb_ctx, NULL, NULL, NULL);
 }
 
-static gboolean
-fpi_poll_is_setup(void)
-{
-	return (fd_added_cb != NULL && fd_removed_cb != NULL);
-}
-
 void
 fpi_timeout_cancel_all_for_dev(struct fp_dev *dev)
 {
diff --git a/libfprint/fpi-sync.c b/libfprint/fpi-sync.c
index e5a64f81..c2dd7927 100644
--- a/libfprint/fpi-sync.c
+++ b/libfprint/fpi-sync.c
@@ -149,7 +149,7 @@ static void enroll_stop_cb(struct fp_dev *dev, void *user_data)
  * or I/O problems.
  *
  * The RETRY codes from #fp_enroll_result may be returned from any enroll
- * stage. These codes indicate that the scan was not succesful in that the
+ * stage. These codes indicate that the scan was not successful in that the
  * user did not position their finger correctly or similar. When a RETRY code
  * is returned, the enrollment stage is <emphasis role="strong">not</emphasis> advanced, so the next call
  * into this function will retry the current stage again. The current stage may
diff --git a/libfprint/fprint.h b/libfprint/fprint.h
index b9b09092..4b68e4aa 100644
--- a/libfprint/fprint.h
+++ b/libfprint/fprint.h
@@ -275,11 +275,13 @@ int fp_identify_finger(struct fp_dev *dev,
 
 /* Data handling */
 int fp_print_data_load(struct fp_dev *dev, enum fp_finger finger,
-	struct fp_print_data **data);
+	struct fp_print_data **data) LIBFPRINT_DEPRECATED;
 int fp_print_data_from_dscv_print(struct fp_dscv_print *print,
 	struct fp_print_data **data) LIBFPRINT_DEPRECATED;
-int fp_print_data_save(struct fp_print_data *data, enum fp_finger finger);
-int fp_print_data_delete(struct fp_dev *dev, enum fp_finger finger);
+int fp_print_data_save(struct fp_print_data *data, enum fp_finger finger)
+	LIBFPRINT_DEPRECATED;
+int fp_print_data_delete(struct fp_dev *dev, enum fp_finger finger)
+	LIBFPRINT_DEPRECATED;
 void fp_print_data_free(struct fp_print_data *data);
 size_t fp_print_data_get_data(struct fp_print_data *data, unsigned char **ret);
 struct fp_print_data *fp_print_data_from_data(unsigned char *buf,
diff --git a/libfprint/meson.build b/libfprint/meson.build
index abd00054..976c70c8 100644
--- a/libfprint/meson.build
+++ b/libfprint/meson.build
@@ -1,40 +1,18 @@
 libfprint_sources = [
-    'fp_internal.h',
-    'nbis-helpers.h',
-    'drivers_api.h',
     'fpi-async.c',
-    'fpi-async.h',
     'fpi-assembling.c',
-    'fpi-assembling.h',
     'fpi-core.c',
-    'fpi-core.h',
     'fpi-data.c',
-    'fpi-data.h',
     'fpi-dev.c',
-    'fpi-dev.h',
     'fpi-dev-img.c',
-    'fpi-dev-img.h',
     'fpi-img.c',
-    'fpi-img.h',
-    'fpi-log.h',
     'fpi-ssm.c',
-    'fpi-ssm.h',
     'fpi-sync.c',
-    'fpi-poll.h',
     'fpi-poll.c',
-    'fpi-usb.h',
     'fpi-usb.c',
-    'drivers/driver_ids.h',
 ]
 
 nbis_sources = [
-    'nbis/include/bozorth.h',
-    'nbis/include/bz_array.h',
-    'nbis/include/defs.h',
-    'nbis/include/lfs.h',
-    'nbis/include/log.h',
-    'nbis/include/morph.h',
-    'nbis/include/sunrast.h',
     'nbis/bozorth3/bozorth3.c',
     'nbis/bozorth3/bz_alloc.c',
     'nbis/bozorth3/bz_drvrs.c',
@@ -76,13 +54,13 @@ drivers_sources = []
 drivers_cflags = []
 foreach driver: drivers
     if driver == 'upekts'
-        drivers_sources += [ 'drivers/upekts.c' ]
+        drivers_sources += [ 'drivers/upekts.c', 'drivers/upek_proto.c' ]
     endif
     if driver == 'upektc'
-        drivers_sources += [ 'drivers/upektc.c', 'drivers/upektc.h', 'drivers/upek_proto.c', 'drivers/upek_proto.h' ]
+        drivers_sources += [ 'drivers/upektc.c' ]
     endif
     if driver == 'upeksonly'
-        drivers_sources += [ 'drivers/upeksonly.c', 'drivers/upeksonly.h' ]
+        drivers_sources += [ 'drivers/upeksonly.c' ]
     endif
     if driver == 'uru4000'
         drivers_sources += [ 'drivers/uru4000.c' ]
@@ -92,20 +70,20 @@ foreach driver: drivers
         aeslib = true
     endif
     if driver == 'aes1660'
-        drivers_sources += [ 'drivers/aes1660.c', 'drivers/aes1660.h' ]
+        drivers_sources += [ 'drivers/aes1660.c' ]
         aeslib = true
         aesx660 = true
     endif
     if driver == 'aes2501'
-        drivers_sources += [ 'drivers/aes2501.c', 'drivers/aes2501.h' ]
+        drivers_sources += [ 'drivers/aes2501.c' ]
         aeslib = true
     endif
     if driver == 'aes2550'
-        drivers_sources += [ 'drivers/aes2550.c', 'drivers/aes2550.h' ]
+        drivers_sources += [ 'drivers/aes2550.c' ]
         aeslib = true
     endif
     if driver == 'aes2660'
-        drivers_sources += [ 'drivers/aes2660.c', 'drivers/aes2660.h' ]
+        drivers_sources += [ 'drivers/aes2660.c' ]
         aeslib = true
         aesx660 = true
     endif
@@ -119,9 +97,6 @@ foreach driver: drivers
         aeslib = true
         aes3k = true
     endif
-    if driver == 'fdu2000'
-        drivers_sources += [ 'drivers/fdu2000.c' ]
-    endif
     if driver == 'vcom5s'
         drivers_sources += [ 'drivers/vcom5s.c' ]
     endif
@@ -129,33 +104,33 @@ foreach driver: drivers
         drivers_sources += [ 'drivers/vfs101.c' ]
     endif
     if driver == 'vfs301'
-        drivers_sources += [ 'drivers/vfs301.c', 'drivers/vfs301_proto.c',  'drivers/vfs301_proto.h', 'drivers/vfs301_proto_fragments.h' ]
+        drivers_sources += [ 'drivers/vfs301.c', 'drivers/vfs301_proto.c' ]
     endif
     if driver == 'vfs5011'
-        drivers_sources += [ 'drivers/vfs5011.c', 'drivers/vfs5011_proto.h' ]
+        drivers_sources += [ 'drivers/vfs5011.c' ]
     endif
     if driver == 'upektc_img'
-        drivers_sources += [ 'drivers/upektc_img.c', 'drivers/upektc_img.h', 'drivers/upek_proto.c', 'drivers/upek_proto.h' ]
+        drivers_sources += [ 'drivers/upektc_img.c',  'drivers/upek_proto.c' ]
     endif
     if driver == 'etes603'
         drivers_sources += [ 'drivers/etes603.c' ]
     endif
     if driver == 'vfs0050'
-        drivers_sources += [ 'drivers/vfs0050.c', 'drivers/vfs0050.h' ]
+        drivers_sources += [ 'drivers/vfs0050.c' ]
     endif
     if driver == 'elan'
-        drivers_sources += [ 'drivers/elan.c', 'drivers/elan.h' ]
+        drivers_sources += [ 'drivers/elan.c' ]
     endif
 endforeach
 
 if aeslib
-    drivers_sources += [ 'drivers/aeslib.c', 'drivers/aeslib.h' ]
+    drivers_sources += [ 'drivers/aeslib.c' ]
 endif
 if aesx660
-    drivers_sources += ['drivers/aesx660.c', 'drivers/aesx660.h' ]
+    drivers_sources += ['drivers/aesx660.c' ]
 endif
 if aes3k
-    drivers_sources += ['drivers/aes3k.c', 'drivers/aes3k.h' ]
+    drivers_sources += ['drivers/aes3k.c' ]
 endif
 
 other_sources = []
diff --git a/meson.build b/meson.build
index db5008f1..b7f7f315 100644
--- a/meson.build
+++ b/meson.build
@@ -1,5 +1,5 @@
 project('libfprint', [ 'c', 'cpp' ],
-        version: '0.99.0',
+        version: '1.0',
         license: 'LGPLv2.1+',
         default_options: [
           'buildtype=debugoptimized',
@@ -27,7 +27,9 @@ common_cflags = cc.get_supported_arguments([
     '-Wstrict-prototypes',
     '-Werror-implicit-function-declaration',
     '-Wno-pointer-sign',
-    '-Wshadow'
+    '-Wshadow',
+    '-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_50',
+    '-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_50',
 ])
 
 # maintaining compatibility with the previous libtool versioning
@@ -39,7 +41,7 @@ revision = 0
 libversion = '@0@.@1@.@2@'.format(soversion, current, revision)
 
 # Dependencies
-glib_dep = dependency('glib-2.0', version: '>= 2.28')
+glib_dep = dependency('glib-2.0', version: '>= 2.50')
 libusb_dep = dependency('libusb-1.0', version: '>= 0.9.1')
 mathlib_dep = cc.find_library('m', required: false)
 
diff --git a/meson_options.txt b/meson_options.txt
index 3e63304b..f40ebc31 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -17,7 +17,7 @@ option('x11-examples',
 option('gtk-examples',
        description: 'Whether to build GTK+ example applications',
        type: 'boolean',
-       value: true)
+       value: false)
 option('doc',
        description: 'Whether to build the API documentation',
        type: 'boolean',