Recommit: Roll libusbx to 1.0.17

Original: https://codereview.chromium.org/24227008/
> Roll libusbx to 1.0.17
>
> R=meacer@chromium.org
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=225105

TBR=meacer@chromium.org,xiyuan@chromium.org

Review URL: https://codereview.chromium.org/24470004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225137 0039d316-1c4b-4281-b951-d872f2087c98

21 files changed, 586 insertions, 290 deletions

diff --git a/third_party/libusb/README.chromium b/third_party/libusb/README.chromium
index 348d919..134cbed 100644
--- a/third_party/libusb/README.chromium
+++ b/third_party/libusb/README.chromium
@@ -1,6 +1,6 @@
 Name: libusbx
 URL: http://libusb.org
-Version: 1.0.16
+Version: 1.0.17
 License: LGPL 2.1
 License File: src/COPYING
 Security Critical: yes
diff --git a/third_party/libusb/src/libusb/core.c b/third_party/libusb/src/libusb/core.c
index e29e8df..e816284 100644
--- a/third_party/libusb/src/libusb/core.c
+++ b/third_party/libusb/src/libusb/core.c
@@ -33,6 +33,9 @@
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
+#ifdef HAVE_SYSLOG_H
+#include <syslog.h>
+#endif
 
 #ifdef __ANDROID__
 #include <android/log.h>
@@ -47,6 +50,8 @@ const struct usbi_os_backend * const usbi_backend = &linux_usbfs_backend;
 const struct usbi_os_backend * const usbi_backend = &darwin_backend;
 #elif defined(OS_OPENBSD)
 const struct usbi_os_backend * const usbi_backend = &openbsd_backend;
+#elif defined(OS_NETBSD)
+const struct usbi_os_backend * const usbi_backend = &netbsd_backend;
 #elif defined(OS_WINDOWS)
 const struct usbi_os_backend * const usbi_backend = &windows_backend;
 #elif defined(OS_WINCE)
@@ -56,7 +61,7 @@ const struct usbi_os_backend * const usbi_backend = &wince_backend;
 #endif
 
 struct libusb_context *usbi_default_context = NULL;
-const struct libusb_version libusb_version_internal =
+static const struct libusb_version libusb_version_internal =
 	{ LIBUSB_MAJOR, LIBUSB_MINOR, LIBUSB_MICRO, LIBUSB_NANO,
 	  LIBUSB_RC, "http://libusbx.org" };
 static int default_context_refcnt = 0;
@@ -564,6 +569,10 @@ void usbi_disconnect_device(struct libusb_device *dev)
 	dev->attached = 0;
 	usbi_mutex_unlock(&dev->lock);
 
+	usbi_mutex_lock(&ctx->usb_devs_lock);
+	list_del(&dev->list);
+	usbi_mutex_unlock(&ctx->usb_devs_lock);
+
 	/* Signal that an event has occurred for this device if we support hotplug AND
 	 * the hotplug pipe is ready. This prevents an event from getting raised during
 	 * initial enumeration. libusb_handle_events will take care of dereferencing the
@@ -574,10 +583,6 @@ void usbi_disconnect_device(struct libusb_device *dev)
 			usbi_err(DEVICE_CTX(dev), "error writing hotplug message");
 		}
 	}
-
-	usbi_mutex_lock(&ctx->usb_devs_lock);
-	list_del(&dev->list);
-	usbi_mutex_unlock(&ctx->usb_devs_lock);
 }
 
 /* Perform some final sanity checks on a newly discovered device. If this
@@ -1873,10 +1878,6 @@ err_free_ctx:
 	if (ctx == usbi_default_context)
 		usbi_default_context = NULL;
 
-	usbi_mutex_destroy(&ctx->open_devs_lock);
-	usbi_mutex_destroy(&ctx->usb_devs_lock);
-	usbi_mutex_destroy(&ctx->hotplug_cbs_lock);
-
 	usbi_mutex_static_lock(&active_contexts_lock);
 	list_del (&ctx->list);
 	usbi_mutex_static_unlock(&active_contexts_lock);
@@ -1888,6 +1889,10 @@ err_free_ctx:
 	}
 	usbi_mutex_unlock(&ctx->usb_devs_lock);
 
+	usbi_mutex_destroy(&ctx->open_devs_lock);
+	usbi_mutex_destroy(&ctx->usb_devs_lock);
+	usbi_mutex_destroy(&ctx->hotplug_cbs_lock);
+
 	free(ctx);
 err_unlock:
 	usbi_mutex_static_unlock(&default_context_lock);
@@ -2026,10 +2031,42 @@ int usbi_gettimeofday(struct timeval *tp, void *tzp)
 }
 #endif
 
-static void usbi_log_str(struct libusb_context *ctx, const char * str)
+static void usbi_log_str(struct libusb_context *ctx,
+	enum libusb_log_level level, const char * str)
 {
-	UNUSED(ctx);
+#if defined(USE_SYSTEM_LOGGING_FACILITY)
+#if defined(OS_WINDOWS) || defined(OS_WINCE)
+	/* Windows CE only supports the Unicode version of OutputDebugString. */
+	WCHAR wbuf[USBI_MAX_LOG_LEN];
+	MultiByteToWideChar(CP_UTF8, 0, str, -1, wbuf, sizeof(wbuf));
+	OutputDebugStringW(wbuf);
+#elif defined(__ANDROID__)
+	int priority = ANDROID_LOG_UNKNOWN;
+	switch (level) {
+	case LIBUSB_LOG_LEVEL_INFO: priority = ANDROID_LOG_INFO; break;
+	case LIBUSB_LOG_LEVEL_WARNING: priority = ANDROID_LOG_WARN; break;
+	case LIBUSB_LOG_LEVEL_ERROR: priority = ANDROID_LOG_ERROR; break;
+	case LIBUSB_LOG_LEVEL_DEBUG: priority = ANDROID_LOG_DEBUG; break;
+	}
+	__android_log_write(priority, "libusb", str);
+#elif defined(HAVE_SYSLOG_FUNC)
+	int syslog_level = LOG_INFO;
+	switch (level) {
+	case LIBUSB_LOG_LEVEL_INFO: syslog_level = LOG_INFO; break;
+	case LIBUSB_LOG_LEVEL_WARNING: syslog_level = LOG_WARNING; break;
+	case LIBUSB_LOG_LEVEL_ERROR: syslog_level = LOG_ERR; break;
+	case LIBUSB_LOG_LEVEL_DEBUG: syslog_level = LOG_DEBUG; break;
+	}
+	syslog(syslog_level, "%s", str);
+#else /* All of gcc, Clang, XCode seem to use #warning */
+#warning System logging is not supported on this platform. Logging to stderr will be used instead.
+	fputs(str, stderr);
+#endif
+#else
 	fputs(str, stderr);
+#endif /* USE_SYSTEM_LOGGING_FACILITY */
+	UNUSED(ctx);
+	UNUSED(level);
 }
 
 void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level,
@@ -2059,33 +2096,11 @@ void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level,
 		return;
 #endif
 
-#ifdef __ANDROID__
-	int prio;
-	switch (level) {
-	case LOG_LEVEL_INFO:
-		prio = ANDROID_LOG_INFO;
-		break;
-	case LOG_LEVEL_WARNING:
-		prio = ANDROID_LOG_WARN;
-		break;
-	case LOG_LEVEL_ERROR:
-		prio = ANDROID_LOG_ERROR;
-		break;
-	case LOG_LEVEL_DEBUG:
-		prio = ANDROID_LOG_DEBUG;
-		break;
-	default:
-		prio = ANDROID_LOG_UNKNOWN;
-		break;
-	}
-
-	__android_log_vprint(prio, "LibUsb", format, args);
-#else
 	usbi_gettimeofday(&now, NULL);
 	if ((global_debug) && (!has_debug_header_been_displayed)) {
 		has_debug_header_been_displayed = 1;
-		usbi_log_str(ctx, "[timestamp] [threadID] facility level [function call] <message>\n");
-		usbi_log_str(ctx, "--------------------------------------------------------------------------------\n");
+		usbi_log_str(ctx, LIBUSB_LOG_LEVEL_DEBUG, "[timestamp] [threadID] facility level [function call] <message>\n");
+		usbi_log_str(ctx, LIBUSB_LOG_LEVEL_DEBUG, "--------------------------------------------------------------------------------\n");
 	}
 	if (now.tv_usec < timestamp_origin.tv_usec) {
 		now.tv_sec--;
@@ -2108,7 +2123,7 @@ void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level,
 		prefix = "debug";
 		break;
 	case LIBUSB_LOG_LEVEL_NONE:
-		break;
+		return;
 	default:
 		prefix = "unknown";
 		break;
@@ -2143,8 +2158,7 @@ void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level,
 	}
 	strcpy(buf + header_len + text_len, USBI_LOG_LINE_END);
 
-	usbi_log_str(ctx, buf);
-#endif
+	usbi_log_str(ctx, level, buf);
 }
 
 void usbi_log(struct libusb_context *ctx, enum libusb_log_level level,
diff --git a/third_party/libusb/src/libusb/descriptor.c b/third_party/libusb/src/libusb/descriptor.c
index ba6d1467..e1c4915 100644
--- a/third_party/libusb/src/libusb/descriptor.c
+++ b/third_party/libusb/src/libusb/descriptor.c
@@ -660,7 +660,7 @@ int API_EXPORTED libusb_get_config_descriptor(libusb_device *dev,
 /* iterate through all configurations, returning the index of the configuration
  * matching a specific bConfigurationValue in the idx output parameter, or -1
  * if the config was not found.
- * returns 0 or a LIBUSB_ERROR code
+ * returns 0 on success or a LIBUSB_ERROR code
  */
 int usbi_get_config_index_by_value(struct libusb_device *dev,
 	uint8_t bConfigurationValue, int *idx)
@@ -673,8 +673,10 @@ int usbi_get_config_index_by_value(struct libusb_device *dev,
 		int host_endian;
 		int r = usbi_backend->get_config_descriptor(dev, i, tmp, sizeof(tmp),
 			&host_endian);
-		if (r < 0)
+		if (r < 0) {
+			*idx = -1;
 			return r;
+		}
 		if (tmp[5] == bConfigurationValue) {
 			*idx = i;
 			return 0;
diff --git a/third_party/libusb/src/libusb/hotplug.c b/third_party/libusb/src/libusb/hotplug.c
index 6b04342..081bc79 100644
--- a/third_party/libusb/src/libusb/hotplug.c
+++ b/third_party/libusb/src/libusb/hotplug.c
@@ -59,7 +59,11 @@
  *
  * A callback function must return an int (0 or 1) indicating whether the callback is
  * expecting additional events. Returning 0 will rearm the callback and 1 will cause
- * the callback to be deregistered.
+ * the callback to be deregistered. Note that when callbacks are called from
+ * libusb_hotplug_register_callback() because of the \ref LIBUSB_HOTPLUG_ENUMERATE
+ * flag, the callback return value is ignored, iow you cannot cause a callback
+ * to be deregistered by returning 1 when it is called from
+ * libusb_hotplug_register_callback().
  *
  * Callbacks for a particular context are automatically deregistered by libusb_exit().
  *
@@ -167,8 +171,7 @@ static int usbi_hotplug_match_cb (struct libusb_context *ctx,
 		return 0;
 	}
 
-	return hotplug_cb->cb (ctx == usbi_default_context ? NULL : ctx,
-			       dev, event, hotplug_cb->user_data);
+	return hotplug_cb->cb (ctx, dev, event, hotplug_cb->user_data);
 }
 
 void usbi_hotplug_match(struct libusb_context *ctx, struct libusb_device *dev,
@@ -192,18 +195,7 @@ void usbi_hotplug_match(struct libusb_context *ctx, struct libusb_device *dev,
 
 	usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
 
-	/* loop through and disconnect all open handles for this device */
-	if (LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT == event) {
-		struct libusb_device_handle *handle;
-
-		usbi_mutex_lock(&ctx->open_devs_lock);
-		list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
-			if (dev == handle->dev) {
-				usbi_handle_disconnect (handle);
-			}
-		}
-		usbi_mutex_unlock(&ctx->open_devs_lock);
-	}
+	/* the backend is expected to call the callback for each active transfer */
 }
 
 int API_EXPORTED libusb_hotplug_register_callback(libusb_context *ctx,
@@ -253,19 +245,29 @@ int API_EXPORTED libusb_hotplug_register_callback(libusb_context *ctx,
 
 	list_add(&new_callback->list, &ctx->hotplug_cbs);
 
-	if (flags & LIBUSB_HOTPLUG_ENUMERATE) {
-		struct libusb_device *dev;
+	usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
 
-		usbi_mutex_lock(&ctx->usb_devs_lock);
 
-		list_for_each_entry(dev, &ctx->usb_devs, list, struct libusb_device) {
-			(void) usbi_hotplug_match_cb (ctx, dev, LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED, new_callback);
+	if (flags & LIBUSB_HOTPLUG_ENUMERATE) {
+		int i, len;
+		struct libusb_device **devs;
+
+		len = (int) libusb_get_device_list(ctx, &devs);
+		if (len < 0) {
+			libusb_hotplug_deregister_callback(ctx,
+							new_callback->handle);
+			return len;
+		}
+
+		for (i = 0; i < len; i++) {
+			usbi_hotplug_match_cb(ctx, devs[i],
+					LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED,
+					new_callback);
 		}
 
-		usbi_mutex_unlock(&ctx->usb_devs_lock);
+		libusb_free_device_list(devs, 1);
 	}
 
-	usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
 
 	if (handle) {
 		*handle = new_callback->handle;
diff --git a/third_party/libusb/src/libusb/io.c b/third_party/libusb/src/libusb/io.c
index 4368b99..4f22963 100644
--- a/third_party/libusb/src/libusb/io.c
+++ b/third_party/libusb/src/libusb/io.c
@@ -787,7 +787,7 @@ void cb(struct libusb_transfer *transfer)
 
 void myfunc() {
 	struct libusb_transfer *transfer;
-	unsigned char buffer[LIBUSB_CONTROL_SETUP_SIZE];
+	unsigned char buffer[LIBUSB_CONTROL_SETUP_SIZE] __attribute__ ((aligned (2)));
 	int completed = 0;
 
 	transfer = libusb_alloc_transfer(0);
@@ -1459,6 +1459,8 @@ int API_EXPORTED libusb_submit_transfer(struct libusb_transfer *transfer)
 	}
 	usbi_mutex_unlock(&ctx->flying_transfers_lock);
 
+	/* keep a reference to this device */
+	libusb_ref_device(transfer->dev_handle->dev);
 out:
 	updated_fds = (itransfer->flags & USBI_TRANSFER_UPDATED_FDS);
 	usbi_mutex_unlock(&itransfer->lock);
@@ -1522,6 +1524,7 @@ int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
 	struct libusb_transfer *transfer =
 		USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	struct libusb_context *ctx = TRANSFER_CTX(transfer);
+	struct libusb_device_handle *handle = transfer->dev_handle;
 	uint8_t flags;
 	int r = 0;
 
@@ -1562,6 +1565,7 @@ int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
 	usbi_mutex_lock(&ctx->event_waiters_lock);
 	usbi_cond_broadcast(&ctx->event_waiters_cond);
 	usbi_mutex_unlock(&ctx->event_waiters_lock);
+	libusb_unref_device(handle->dev);
 	return 0;
 }
 
@@ -1996,8 +2000,8 @@ static int handle_events(struct libusb_context *ctx, struct timeval *tv)
 
 		/* read the message from the hotplug thread */
 		ret = usbi_read(ctx->hotplug_pipe[0], &message, sizeof (message));
-		if (ret < sizeof(message)) {
-			usbi_err(ctx, "hotplug pipe read error %d < %d",
+		if (ret != sizeof(message)) {
+			usbi_err(ctx, "hotplug pipe read error %d != %u",
 				 ret, sizeof(message));
 			r = LIBUSB_ERROR_OTHER;
 			goto handled;
diff --git a/third_party/libusb/src/libusb/libusb.h b/third_party/libusb/src/libusb/libusb.h
index 15bd0d5..d144b3e 100644
--- a/third_party/libusb/src/libusb/libusb.h
+++ b/third_party/libusb/src/libusb/libusb.h
@@ -156,7 +156,7 @@ typedef unsigned __int32  uint32_t;
 extern "C" {
 #endif
 
-/** \def libusb_cpu_to_le16
+/** \fn libusb_cpu_to_le16
  * \ingroup misc
  * Convert a 16-bit value from host-endian to little-endian format. On
  * little endian systems, this function does nothing. On big endian systems,
@@ -1434,7 +1434,7 @@ static inline unsigned char *libusb_control_transfer_get_data(
 static inline struct libusb_control_setup *libusb_control_transfer_get_setup(
 	struct libusb_transfer *transfer)
 {
-	return (struct libusb_control_setup *) transfer->buffer;
+	return (struct libusb_control_setup *)(void *) transfer->buffer;
 }
 
 /** \ingroup asyncio
@@ -1443,6 +1443,7 @@ static inline struct libusb_control_setup *libusb_control_transfer_get_setup(
  * be given in host-endian byte order.
  *
  * \param buffer buffer to output the setup packet into
+ * This pointer must be aligned to at least 2 bytes boundary.
  * \param bmRequestType see the
  * \ref libusb_control_setup::bmRequestType "bmRequestType" field of
  * \ref libusb_control_setup
@@ -1463,7 +1464,7 @@ static inline void libusb_fill_control_setup(unsigned char *buffer,
 	uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
 	uint16_t wLength)
 {
-	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
+	struct libusb_control_setup *setup = (struct libusb_control_setup *)(void *) buffer;
 	setup->bmRequestType = bmRequestType;
 	setup->bRequest = bRequest;
 	setup->wValue = libusb_cpu_to_le16(wValue);
@@ -1499,6 +1500,7 @@ void LIBUSB_CALL libusb_free_transfer(struct libusb_transfer *transfer);
  * \param dev_handle handle of the device that will handle the transfer
  * \param buffer data buffer. If provided, this function will interpret the
  * first 8 bytes as a setup packet and infer the transfer length from that.
+ * This pointer must be aligned to at least 2 bytes boundary.
  * \param callback callback function to be invoked on transfer completion
  * \param user_data user data to pass to callback function
  * \param timeout timeout for the transfer in milliseconds
@@ -1508,7 +1510,7 @@ static inline void libusb_fill_control_transfer(
 	unsigned char *buffer, libusb_transfer_cb_fn callback, void *user_data,
 	unsigned int timeout)
 {
-	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
+	struct libusb_control_setup *setup = (struct libusb_control_setup *)(void *) buffer;
 	transfer->dev_handle = dev_handle;
 	transfer->endpoint = 0;
 	transfer->type = LIBUSB_TRANSFER_TYPE_CONTROL;
@@ -1883,7 +1885,7 @@ typedef enum {
  *
  * Since version 1.0.16, \ref LIBUSBX_API_VERSION >= 0x01000102
  *
- * \param libusb_context context of this notification
+ * \param ctx            context of this notification
  * \param device         libusb_device this event occurred on
  * \param event          event that occurred
  * \param user_data      user data provided when this callback was registered
@@ -1903,6 +1905,18 @@ typedef int (LIBUSB_CALL *libusb_hotplug_callback_fn)(libusb_context *ctx,
  * armed until either it is deregistered with libusb_hotplug_deregister_callback()
  * or the supplied callback returns 1 to indicate it is finished processing events.
  *
+ * If the \ref LIBUSB_HOTPLUG_ENUMERATE is passed the callback will be
+ * called with a \ref LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED for all devices
+ * already plugged into the machine. Note that libusbx modifies its internal
+ * device list from a separate thread, while calling hotplug callbacks from
+ * libusb_handle_events(), so it is possible for a device to already be present
+ * on, or removed from, its internal device list, while the hotplug callbacks
+ * still need to be dispatched. This means that when using \ref
+ * LIBUSB_HOTPLUG_ENUMERATE, your callback may be called twice for the arrival
+ * of the same device, once from libusb_hotplug_register_callback() and once
+ * from libusb_handle_events(); and/or your callback may be called for the
+ * removal of a device for which an arrived call was never made.
+ *
  * Since version 1.0.16, \ref LIBUSBX_API_VERSION >= 0x01000102
  *
  * \param[in] ctx context to register this callback with
diff --git a/third_party/libusb/src/libusb/libusbi.h b/third_party/libusb/src/libusb/libusbi.h
index 02efae30..bc608b92 100644
--- a/third_party/libusb/src/libusb/libusbi.h
+++ b/third_party/libusb/src/libusb/libusbi.h
@@ -23,6 +23,8 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+
 #include <stddef.h>
 #include <stdint.h>
 #include <time.h>
@@ -433,7 +435,7 @@ void usbi_connect_device (struct libusb_device *dev);
 void usbi_disconnect_device (struct libusb_device *dev);
 
 /* Internal abstraction for poll (needs struct usbi_transfer on Windows) */
-#if defined(OS_LINUX) || defined(OS_DARWIN) || defined(OS_OPENBSD)
+#if defined(OS_LINUX) || defined(OS_DARWIN) || defined(OS_OPENBSD) || defined(OS_NETBSD)
 #include <unistd.h>
 #include "os/poll_posix.h"
 #elif defined(OS_WINDOWS) || defined(OS_WINCE)
@@ -995,6 +997,7 @@ extern const struct usbi_os_backend * const usbi_backend;
 extern const struct usbi_os_backend linux_usbfs_backend;
 extern const struct usbi_os_backend darwin_backend;
 extern const struct usbi_os_backend openbsd_backend;
+extern const struct usbi_os_backend netbsd_backend;
 extern const struct usbi_os_backend windows_backend;
 extern const struct usbi_os_backend wince_backend;
 
diff --git a/third_party/libusb/src/libusb/os/darwin_usb.c b/third_party/libusb/src/libusb/os/darwin_usb.c
index 3f315e8..58467c3 100644
--- a/third_party/libusb/src/libusb/os/darwin_usb.c
+++ b/third_party/libusb/src/libusb/os/darwin_usb.c
@@ -210,6 +210,7 @@ static int usb_setup_device_iterator (io_iterator_t *deviceIterator, UInt32 loca
   return IOServiceGetMatchingServices(kIOMasterPortDefault, matchingDict, deviceIterator);
 }
 
+/* Returns 1 on success, 0 on failure. */
 static int get_ioregistry_value_number (io_service_t service, CFStringRef property, CFNumberType type, void *p) {
   CFTypeRef cfNumber = IORegistryEntryCreateCFProperty (service, property, kCFAllocatorDefault, 0);
   int ret = 0;
@@ -287,7 +288,7 @@ static void darwin_devices_detached (void *ptr, io_iterator_t rem_devices) {
     list_for_each_entry(ctx, &active_contexts_list, list, struct libusb_context) {
       usbi_dbg ("notifying context %p of device disconnect", ctx);
 
-      dev = usbi_get_device_by_session_id(ctx, session);
+      dev = usbi_get_device_by_session_id(ctx, (unsigned long) session);
       if (dev) {
         /* signal the core that this device has been disconnected. the core will tear down this device
            when the reference count reaches 0 */
@@ -701,7 +702,7 @@ static int darwin_cache_device_descriptor (struct libusb_context *ctx, struct da
     else
       usbi_warn (ctx, "could not retrieve device descriptor %.4x:%.4x: %s (%x). skipping device",
                  idVendor, idProduct, darwin_error_str (ret), ret);
-    return -1;
+    return darwin_to_libusb (ret);
   }
 
   /* catch buggy hubs (which appear to be virtual). Apple's own USB prober has problems with these devices. */
@@ -709,7 +710,7 @@ static int darwin_cache_device_descriptor (struct libusb_context *ctx, struct da
     /* not a valid device */
     usbi_warn (ctx, "idProduct from iokit (%04x) does not match idProduct in descriptor (%04x). skipping device",
                idProduct, libusb_le16_to_cpu (dev->dev_descriptor.idProduct));
-    return -1;
+    return LIBUSB_ERROR_NO_DEVICE;
   }
 
   usbi_dbg ("cached device descriptor:");
@@ -729,21 +730,19 @@ static int darwin_cache_device_descriptor (struct libusb_context *ctx, struct da
 
   dev->can_enumerate = 1;
 
-  return 0;
+  return LIBUSB_SUCCESS;
 }
 
 static int darwin_get_cached_device(struct libusb_context *ctx, io_service_t service,
                                     struct darwin_cached_device **cached_out) {
   struct darwin_cached_device *new_device;
-  UInt64 sessionID, parent_sessionID;
+  UInt64 sessionID = 0, parent_sessionID = 0;
   int ret = LIBUSB_SUCCESS;
   usb_device_t **device;
   io_service_t parent;
   kern_return_t result;
   UInt8 port = 0;
 
-  *cached_out = NULL;
-
   /* get some info from the io registry */
   (void) get_ioregistry_value_number (service, CFSTR("sessionID"), kCFNumberSInt64Type, &sessionID);
   (void) get_ioregistry_value_number (service, CFSTR("PortNum"), kCFNumberSInt8Type, &port);
@@ -759,6 +758,8 @@ static int darwin_get_cached_device(struct libusb_context *ctx, io_service_t ser
 
   usbi_mutex_lock(&darwin_cached_devices_lock);
   do {
+    *cached_out = NULL;
+
     list_for_each_entry(new_device, &darwin_cached_devices, list, struct darwin_cached_device) {
       usbi_dbg("matching sessionID 0x%x against cached device with sessionID 0x%x", sessionID, new_device->session);
       if (new_device->session == sessionID) {
@@ -773,17 +774,15 @@ static int darwin_get_cached_device(struct libusb_context *ctx, io_service_t ser
 
     usbi_dbg("caching new device with sessionID 0x%x\n", sessionID);
 
-    new_device = calloc (1, sizeof (*new_device));
-    if (!new_device) {
-      ret = LIBUSB_ERROR_NO_MEM;
-      break;
-    }
-
     device = darwin_device_from_service (service);
     if (!device) {
       ret = LIBUSB_ERROR_NO_DEVICE;
-      free (new_device);
-      new_device = NULL;
+      break;
+    }
+
+    new_device = calloc (1, sizeof (*new_device));
+    if (!new_device) {
+      ret = LIBUSB_ERROR_NO_MEM;
       break;
     }
 
@@ -833,7 +832,7 @@ static int process_new_device (struct libusb_context *ctx, io_service_t service)
   do {
     ret = darwin_get_cached_device (ctx, service, &cached_device);
 
-    if (ret < 0 || (cached_device && !cached_device->can_enumerate)) {
+    if (ret < 0 || !cached_device->can_enumerate) {
       return ret;
     }
 
@@ -846,7 +845,7 @@ static int process_new_device (struct libusb_context *ctx, io_service_t service)
     usbi_dbg ("allocating new device in context %p for with session 0x%08x",
               ctx, cached_device->session);
 
-    dev = usbi_alloc_device(ctx, cached_device->session);
+    dev = usbi_alloc_device(ctx, (unsigned long) cached_device->session);
     if (!dev) {
       return LIBUSB_ERROR_NO_MEM;
     }
@@ -857,7 +856,7 @@ static int process_new_device (struct libusb_context *ctx, io_service_t service)
     darwin_ref_cached_device (priv->dev);
 
     if (cached_device->parent_session > 0) {
-      dev->parent_dev = usbi_get_device_by_session_id (ctx, cached_device->parent_session);
+      dev->parent_dev = usbi_get_device_by_session_id (ctx, (unsigned long) cached_device->parent_session);
     } else {
       dev->parent_dev = NULL;
     }
diff --git a/third_party/libusb/src/libusb/os/linux_netlink.c b/third_party/libusb/src/libusb/os/linux_netlink.c
index 3a68f69..f1c1be1 100644
--- a/third_party/libusb/src/libusb/os/linux_netlink.c
+++ b/third_party/libusb/src/libusb/os/linux_netlink.c
@@ -21,6 +21,10 @@
  */
 
 #include "config.h"
+#include "libusb.h"
+#include "libusbi.h"
+#include "linux_usbfs.h"
+
 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
@@ -30,46 +34,113 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+
+#ifdef HAVE_ASM_TYPES_H
+#include <asm/types.h>
+#endif
+
+#ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
-#include <arpa/inet.h>
+#endif
 
-#include "libusb.h"
-#include "libusbi.h"
-#include "linux_usbfs.h"
+#include <arpa/inet.h>
 
+#ifdef HAVE_LINUX_NETLINK_H
 #include <linux/netlink.h>
+#endif
+
+#ifdef HAVE_LINUX_FILTER_H
 #include <linux/filter.h>
+#endif
 
 #define KERNEL 1
 
 static int linux_netlink_socket = -1;
+static int netlink_control_pipe[2] = { -1, -1 };
 static pthread_t libusb_linux_event_thread;
 
 static void *linux_netlink_event_thread_main(void *arg);
 
 struct sockaddr_nl snl = { .nl_family=AF_NETLINK, .nl_groups=KERNEL };
 
+static int set_fd_cloexec_nb (int fd)
+{
+	int flags;
+
+#if defined(FD_CLOEXEC)
+	flags = fcntl (linux_netlink_socket, F_GETFD);
+	if (0 > flags) {
+		return -1;
+	}
+
+	if (!(flags & FD_CLOEXEC)) {
+		fcntl (linux_netlink_socket, F_SETFD, flags | FD_CLOEXEC);
+	}
+#endif
+
+	flags = fcntl (linux_netlink_socket, F_GETFL);
+	if (0 > flags) {
+		return -1;
+	}
+
+	if (!(flags & O_NONBLOCK)) {
+		fcntl (linux_netlink_socket, F_SETFL, flags | O_NONBLOCK);
+	}
+
+	return 0;
+}
+
 int linux_netlink_start_event_monitor(void)
 {
+	int socktype = SOCK_RAW;
 	int ret;
 
 	snl.nl_groups = KERNEL;
 
-	linux_netlink_socket = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_KOBJECT_UEVENT);
+#if defined(SOCK_CLOEXEC)
+	socktype |= SOCK_CLOEXEC;
+#endif
+#if defined(SOCK_NONBLOCK)
+	socktype |= SOCK_NONBLOCK;
+#endif
+
+	linux_netlink_socket = socket(PF_NETLINK, socktype, NETLINK_KOBJECT_UEVENT);
+	if (-1 == linux_netlink_socket && EINVAL == errno) {
+		linux_netlink_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_KOBJECT_UEVENT);
+	}
+
 	if (-1 == linux_netlink_socket) {
 		return LIBUSB_ERROR_OTHER;
 	}
 
+	ret = set_fd_cloexec_nb (linux_netlink_socket);
+	if (0 != ret) {
+		close (linux_netlink_socket);
+		linux_netlink_socket = -1;
+		return LIBUSB_ERROR_OTHER;
+	}
+
 	ret = bind(linux_netlink_socket, (struct sockaddr *) &snl, sizeof(snl));
 	if (0 != ret) {
+	        close(linux_netlink_socket);
 		return LIBUSB_ERROR_OTHER;
 	}
 
 	/* TODO -- add authentication */
 	/* setsockopt(linux_netlink_socket, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)); */
 
+	ret = usbi_pipe(netlink_control_pipe);
+	if (ret) {
+		usbi_err(NULL, "could not create netlink control pipe");
+	        close(linux_netlink_socket);
+		return LIBUSB_ERROR_OTHER;
+	}
+
 	ret = pthread_create(&libusb_linux_event_thread, NULL, linux_netlink_event_thread_main, NULL);
 	if (0 != ret) {
+        	close(netlink_control_pipe[0]);
+        	close(netlink_control_pipe[1]);
+	        close(linux_netlink_socket);
 		return LIBUSB_ERROR_OTHER;
 	}
 
@@ -79,22 +150,30 @@ int linux_netlink_start_event_monitor(void)
 int linux_netlink_stop_event_monitor(void)
 {
 	int r;
+	char dummy = 1;
 
 	if (-1 == linux_netlink_socket) {
 		/* already closed. nothing to do */
 		return LIBUSB_SUCCESS;
 	}
 
-	r = close(linux_netlink_socket);
-	if (0 > r) {
-		usbi_err(NULL, "error closing netlink socket. %s", strerror(errno));
-		return LIBUSB_ERROR_OTHER;
+	/* Write some dummy data to the control pipe and
+	 * wait for the thread to exit */
+	r = usbi_write(netlink_control_pipe[1], &dummy, sizeof(dummy));
+	if (r <= 0) {
+		usbi_warn(NULL, "netlink control pipe signal failed");
 	}
+	pthread_join(libusb_linux_event_thread, NULL);
 
-	pthread_cancel(libusb_linux_event_thread);
-
+	close(linux_netlink_socket);
 	linux_netlink_socket = -1;
 
+	/* close and reset control pipe */
+	close(netlink_control_pipe[0]);
+	close(netlink_control_pipe[1]);
+	netlink_control_pipe[0] = -1;
+	netlink_control_pipe[1] = -1;
+
 	return LIBUSB_SUCCESS;
 }
 
@@ -214,7 +293,7 @@ static int linux_netlink_read_message(void)
 
 	/* signal device is available (or not) to all contexts */
 	if (detached)
-		linux_hotplug_disconnected(busnum, devaddr, sys_name);
+		linux_device_disconnected(busnum, devaddr, sys_name);
 	else
 		linux_hotplug_enumerate(busnum, devaddr, sys_name);
 
@@ -223,20 +302,32 @@ static int linux_netlink_read_message(void)
 
 static void *linux_netlink_event_thread_main(void *arg)
 {
-	struct pollfd fds = {.fd = linux_netlink_socket,
-			     .events = POLLIN};
+	char dummy;
+	int r;
+	struct pollfd fds[] = {
+		{ .fd = netlink_control_pipe[0],
+		  .events = POLLIN },
+		{ .fd = linux_netlink_socket,
+		  .events = POLLIN },
+	};
 
 	/* silence compiler warning */
 	(void) arg;
 
-	while (1 == poll(&fds, 1, -1)) {
-		if (POLLIN != fds.revents) {
+	while (poll(fds, 2, -1) >= 0) {
+		if (fds[0].revents & POLLIN) {
+			/* activity on control pipe, read the byte and exit */
+			r = usbi_read(netlink_control_pipe[0], &dummy, sizeof(dummy));
+			if (r <= 0) {
+				usbi_warn(NULL, "netlink control pipe read failed");
+			}
 			break;
 		}
-
-		usbi_mutex_static_lock(&linux_hotplug_lock);
-		linux_netlink_read_message();
-		usbi_mutex_static_unlock(&linux_hotplug_lock);
+		if (fds[1].revents & POLLIN) {
+        		usbi_mutex_static_lock(&linux_hotplug_lock);
+	        	linux_netlink_read_message();
+	        	usbi_mutex_static_unlock(&linux_hotplug_lock);
+		}
 	}
 
 	return NULL;
diff --git a/third_party/libusb/src/libusb/os/linux_udev.c b/third_party/libusb/src/libusb/os/linux_udev.c
index 5a2aadf..99ac943 100644
--- a/third_party/libusb/src/libusb/os/linux_udev.c
+++ b/third_party/libusb/src/libusb/os/linux_udev.c
@@ -46,6 +46,7 @@
 /* udev context */
 static struct udev *udev_ctx = NULL;
 static int udev_monitor_fd = -1;
+static int udev_control_pipe[2] = {-1, -1};
 static struct udev_monitor *udev_monitor = NULL;
 static pthread_t linux_event_thread;
 
@@ -95,14 +96,23 @@ int linux_udev_start_event_monitor(void)
 		goto err_free_monitor;
 	}
 
+	r = usbi_pipe(udev_control_pipe);
+	if (r) {
+		usbi_err(NULL, "could not create udev control pipe");
+		goto err_free_monitor;
+	}
+
 	r = pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL);
 	if (r) {
 		usbi_err(NULL, "creating hotplug event thread (%d)", r);
-		goto err_free_monitor;
+		goto err_close_pipe;
 	}
 
 	return LIBUSB_SUCCESS;
 
+err_close_pipe:
+	close(udev_control_pipe[0]);
+	close(udev_control_pipe[1]);
 err_free_monitor:
 	udev_monitor_unref(udev_monitor);
 	udev_monitor = NULL;
@@ -115,14 +125,19 @@ err_free_ctx:
 
 int linux_udev_stop_event_monitor(void)
 {
+	char dummy = 1;
+	int r;
+
 	assert(udev_ctx != NULL);
 	assert(udev_monitor != NULL);
 	assert(udev_monitor_fd != -1);
 
-	/* Cancel the event thread. This is the only way to guarantee the
-	   thread exits since closing the monitor fd won't necessarily cause
-	   poll to return. */
-	pthread_cancel(linux_event_thread);
+	/* Write some dummy data to the control pipe and
+	 * wait for the thread to exit */
+	r = usbi_write(udev_control_pipe[1], &dummy, sizeof(dummy));
+	if (r <= 0) {
+		usbi_warn(NULL, "udev control pipe signal failed");
+	}
 	pthread_join(linux_event_thread, NULL);
 
 	/* Release the udev monitor */
@@ -134,27 +149,45 @@ int linux_udev_stop_event_monitor(void)
 	udev_unref(udev_ctx);
 	udev_ctx = NULL;
 
+	/* close and reset control pipe */
+	close(udev_control_pipe[0]);
+	close(udev_control_pipe[1]);
+	udev_control_pipe[0] = -1;
+	udev_control_pipe[1] = -1;
+
 	return LIBUSB_SUCCESS;
 }
 
 static void *linux_udev_event_thread_main(void *arg)
 {
+	char dummy;
+	int r;
 	struct udev_device* udev_dev;
-	struct pollfd fds = {.fd = udev_monitor_fd,
-			     .events = POLLIN};
+	struct pollfd fds[] = {
+		{.fd = udev_control_pipe[0],
+		 .events = POLLIN},
+		{.fd = udev_monitor_fd,
+		 .events = POLLIN},
+	};
 
 	usbi_dbg("udev event thread entering.");
 
-	while (1 == poll(&fds, 1, -1)) {
-		if (NULL == udev_monitor || POLLIN != fds.revents) {
+	while (poll(fds, 2, -1) >= 0) {
+		if (fds[0].revents & POLLIN) {
+			/* activity on control pipe, read the byte and exit */
+			r = usbi_read(udev_control_pipe[0], &dummy, sizeof(dummy));
+			if (r <= 0) {
+				usbi_warn(NULL, "udev control pipe read failed");
+			}
 			break;
 		}
-
-		usbi_mutex_static_lock(&linux_hotplug_lock);
-		udev_dev = udev_monitor_receive_device(udev_monitor);
-		if (udev_dev)
-			udev_hotplug_event(udev_dev);
-		usbi_mutex_static_unlock(&linux_hotplug_lock);
+		if (fds[1].revents & POLLIN) {
+			usbi_mutex_static_lock(&linux_hotplug_lock);
+			udev_dev = udev_monitor_receive_device(udev_monitor);
+			if (udev_dev)
+				udev_hotplug_event(udev_dev);
+			usbi_mutex_static_unlock(&linux_hotplug_lock);
+		}
 	}
 
 	usbi_dbg("udev event thread exiting");
@@ -207,7 +240,7 @@ static void udev_hotplug_event(struct udev_device* udev_dev)
 		if (strncmp(udev_action, "add", 3) == 0) {
 			linux_hotplug_enumerate(busnum, devaddr, sys_name);
 		} else if (detached) {
-			linux_hotplug_disconnected(busnum, devaddr, sys_name);
+			linux_device_disconnected(busnum, devaddr, sys_name);
 		} else {
 			usbi_err(NULL, "ignoring udev action %s", udev_action);
 		}
diff --git a/third_party/libusb/src/libusb/os/linux_usbfs.c b/third_party/libusb/src/libusb/os/linux_usbfs.c
index 09288af..142fa2b 100644
--- a/third_party/libusb/src/libusb/os/linux_usbfs.c
+++ b/third_party/libusb/src/libusb/os/linux_usbfs.c
@@ -1,3 +1,4 @@
+/* -*- Mode: C; c-basic-offset:8 ; indent-tabs-mode:t -*- */
 /*
  * Linux usbfs backend for libusbx
  * Copyright © 2007-2009 Daniel Drake <dsd@gentoo.org>
@@ -120,7 +121,9 @@ static int sysfs_has_descriptors = -1;
 /* how many times have we initted (and not exited) ? */
 static volatile int init_count = 0;
 
-/* Serialize hotplug start/stop, scan-devices, event-thread, and poll */
+/* Serialize hotplug start/stop */
+usbi_mutex_static_t linux_hotplug_startstop_lock = USBI_MUTEX_INITIALIZER;
+/* Serialize scan-devices, event-thread, and poll */
 usbi_mutex_static_t linux_hotplug_lock = USBI_MUTEX_INITIALIZER;
 
 static int linux_start_event_monitor(void);
@@ -419,7 +422,7 @@ static int op_init(struct libusb_context *ctx)
 	if (sysfs_has_descriptors)
 		usbi_dbg("sysfs has complete descriptors");
 
-	usbi_mutex_static_lock(&linux_hotplug_lock);
+	usbi_mutex_static_lock(&linux_hotplug_startstop_lock);
 	r = LIBUSB_SUCCESS;
 	if (init_count == 0) {
 		/* start up hotplug event handler */
@@ -433,20 +436,20 @@ static int op_init(struct libusb_context *ctx)
 			linux_stop_event_monitor();
 	} else
 		usbi_err(ctx, "error starting hotplug event monitor");
-	usbi_mutex_static_unlock(&linux_hotplug_lock);
+	usbi_mutex_static_unlock(&linux_hotplug_startstop_lock);
 
 	return r;
 }
 
 static void op_exit(void)
 {
-	usbi_mutex_static_lock(&linux_hotplug_lock);
+	usbi_mutex_static_lock(&linux_hotplug_startstop_lock);
 	assert(init_count != 0);
 	if (!--init_count) {
 		/* tear down event handler */
 		(void)linux_stop_event_monitor();
 	}
-	usbi_mutex_static_unlock(&linux_hotplug_lock);
+	usbi_mutex_static_unlock(&linux_hotplug_startstop_lock);
 }
 
 static int linux_start_event_monitor(void)
@@ -469,11 +472,19 @@ static int linux_stop_event_monitor(void)
 
 static int linux_scan_devices(struct libusb_context *ctx)
 {
+	int ret;
+
+	usbi_mutex_static_lock(&linux_hotplug_lock);
+
 #if defined(USE_UDEV)
-	return linux_udev_scan_devices(ctx);
+	ret = linux_udev_scan_devices(ctx);
 #else
-	return linux_default_scan_devices(ctx);
+	ret = linux_default_scan_devices(ctx);
 #endif
+
+	usbi_mutex_static_unlock(&linux_hotplug_lock);
+
+	return ret;
 }
 
 static void op_hotplug_poll(void)
@@ -596,6 +607,8 @@ int linux_get_device_address (struct libusb_context *ctx, int detached,
 	uint8_t *busnum, uint8_t *devaddr,const char *dev_node,
 	const char *sys_name)
 {
+	int sysfs_attr;
+
 	usbi_dbg("getting address for device: %s detached: %d", sys_name, detached);
 	/* can't use sysfs to read the bus and device number if the
 	 * device has been detached */
@@ -616,17 +629,22 @@ int linux_get_device_address (struct libusb_context *ctx, int detached,
 
 	usbi_dbg("scan %s", sys_name);
 
-	*busnum = __read_sysfs_attr(ctx, sys_name, "busnum");
-	if (0 > *busnum)
-		return *busnum;
+	sysfs_attr = __read_sysfs_attr(ctx, sys_name, "busnum");
+	if (0 > sysfs_attr)
+		return sysfs_attr;
+	if (sysfs_attr > 255)
+		return LIBUSB_ERROR_INVALID_PARAM;
+	*busnum = (uint8_t) sysfs_attr;
+
+	sysfs_attr = __read_sysfs_attr(ctx, sys_name, "devnum");
+	if (0 > sysfs_attr)
+		return sysfs_attr;
+	if (sysfs_attr > 255)
+		return LIBUSB_ERROR_INVALID_PARAM;
 
-	*devaddr = __read_sysfs_attr(ctx, sys_name, "devnum");
-	if (0 > *devaddr)
-		return *devaddr;
+	*devaddr = (uint8_t) sysfs_attr;
 
 	usbi_dbg("bus=%d dev=%d", *busnum, *devaddr);
-	if (*busnum > 255 || *devaddr > 255)
-		return LIBUSB_ERROR_INVALID_PARAM;
 
 	return LIBUSB_SUCCESS;
 }
@@ -1072,7 +1090,7 @@ void linux_hotplug_enumerate(uint8_t busnum, uint8_t devaddr, const char *sys_na
 	usbi_mutex_static_unlock(&active_contexts_lock);
 }
 
-void linux_hotplug_disconnected(uint8_t busnum, uint8_t devaddr, const char *sys_name)
+void linux_device_disconnected(uint8_t busnum, uint8_t devaddr, const char *sys_name)
 {
 	struct libusb_context *ctx;
 	struct libusb_device *dev;
@@ -1247,8 +1265,20 @@ static int op_open(struct libusb_device_handle *handle)
 	int r;
 
 	hpriv->fd = _get_usbfs_fd(handle->dev, O_RDWR, 0);
-	if (hpriv->fd < 0)
+	if (hpriv->fd < 0) {
+		if (hpriv->fd == LIBUSB_ERROR_NO_DEVICE) {
+			/* device will still be marked as attached if hotplug monitor thread
+			 * hasn't processed remove event yet */
+			usbi_mutex_static_lock(&linux_hotplug_lock);
+			if (handle->dev->attached) {
+				usbi_dbg("open failed with no device, but device still attached");
+				linux_device_disconnected(handle->dev->bus_number,
+						handle->dev->device_address, NULL);
+			}
+			usbi_mutex_static_unlock(&linux_hotplug_lock);
+		}
 		return hpriv->fd;
+	}
 
 	r = ioctl(hpriv->fd, IOCTL_USBFS_GET_CAPABILITIES, &hpriv->caps);
 	if (r < 0) {
@@ -2482,6 +2512,13 @@ static int op_handle_events(struct libusb_context *ctx,
 		if (pollfd->revents & POLLERR) {
 			usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->fd);
 			usbi_handle_disconnect(handle);
+			/* device will still be marked as attached if hotplug monitor thread
+			 * hasn't processed remove event yet */
+			usbi_mutex_static_lock(&linux_hotplug_lock);
+			if (handle->dev->attached)
+				linux_device_disconnected(handle->dev->bus_number,
+						handle->dev->device_address, NULL);
+			usbi_mutex_static_unlock(&linux_hotplug_lock);
 			continue;
 		}
 
diff --git a/third_party/libusb/src/libusb/os/linux_usbfs.h b/third_party/libusb/src/libusb/os/linux_usbfs.h
index 499bab7..1f5b191 100644
--- a/third_party/libusb/src/libusb/os/linux_usbfs.h
+++ b/third_party/libusb/src/libusb/os/linux_usbfs.h
@@ -170,7 +170,7 @@ void linux_netlink_hotplug_poll(void);
 #endif
 
 void linux_hotplug_enumerate(uint8_t busnum, uint8_t devaddr, const char *sys_name);
-void linux_hotplug_disconnected(uint8_t busnum, uint8_t devaddr, const char *sys_name);
+void linux_device_disconnected(uint8_t busnum, uint8_t devaddr, const char *sys_name);
 
 int linux_get_device_address (struct libusb_context *ctx, int detached,
 	uint8_t *busnum, uint8_t *devaddr, const char *dev_node,
diff --git a/third_party/libusb/src/libusb/os/openbsd_usb.c b/third_party/libusb/src/libusb/os/openbsd_usb.c
index f4fd454..2997e53 100644
--- a/third_party/libusb/src/libusb/os/openbsd_usb.c
+++ b/third_party/libusb/src/libusb/os/openbsd_usb.c
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2011 Martin Pieuchot <mpi@openbsd.org>
+ * Copyright © 2011-2013 Martin Pieuchot <mpi@openbsd.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -32,8 +32,8 @@
 #include "libusbi.h"
 
 struct device_priv {
-	char devnode[16];
-	int fd;
+	char *devname;				/* name of the ugen(4) node */
+	int fd;					/* device file descriptor */
 
 	unsigned char *cdesc;			/* active config descriptor */
 	usb_device_descriptor_t ddesc;		/* usb device descriptor */
@@ -82,11 +82,14 @@ static int obsd_clock_gettime(int, struct timespec *);
  * Private functions
  */
 static int _errno_to_libusb(int);
-static int _cache_active_config_descriptor(struct libusb_device *, int);
+static int _cache_active_config_descriptor(struct libusb_device *);
 static int _sync_control_transfer(struct usbi_transfer *);
 static int _sync_gen_transfer(struct usbi_transfer *);
 static int _access_endpoint(struct libusb_transfer *);
 
+static int _bus_open(int);
+
+
 const struct usbi_os_backend openbsd_backend = {
 	"Synchronous OpenBSD backend",
 	0,
@@ -131,79 +134,105 @@ const struct usbi_os_backend openbsd_backend = {
 	0,				/* add_iso_packet_size */
 };
 
+#define DEVPATH	"/dev/"
+#define USBDEV	DEVPATH "usb"
+
 int
 obsd_get_device_list(struct libusb_context * ctx,
 	struct discovered_devs **discdevs)
 {
+	struct discovered_devs *ddd;
 	struct libusb_device *dev;
 	struct device_priv *dpriv;
 	struct usb_device_info di;
+	struct usb_device_ddesc dd;
 	unsigned long session_id;
-	char devnode[16];
-	int fd, err, i;
+	char devices[USB_MAX_DEVICES];
+	char busnode[16];
+	char *udevname;
+	int fd, addr, i, j;
 
 	usbi_dbg("");
 
-	/* Only ugen(4) is supported */
-	for (i = 0; i < USB_MAX_DEVICES; i++) {
-		/* Control endpoint is always .00 */
-		snprintf(devnode, sizeof(devnode), "/dev/ugen%d.00", i);
+	for (i = 0; i < 8; i++) {
+		snprintf(busnode, sizeof(busnode), USBDEV "%d", i);
 
-		if ((fd = open(devnode, O_RDONLY)) < 0) {
+		if ((fd = open(busnode, O_RDWR)) < 0) {
 			if (errno != ENOENT && errno != ENXIO)
-				usbi_err(ctx, "could not open %s", devnode);
+				usbi_err(ctx, "could not open %s", busnode);
 			continue;
 		}
 
-		if (ioctl(fd, USB_GET_DEVICEINFO, &di) < 0)
-			continue;
-
-		session_id = (di.udi_bus << 8 | di.udi_addr);
-		dev = usbi_get_device_by_session_id(ctx, session_id);
-
-		if (dev) {
-			dev = libusb_ref_device(dev);
-		} else {
-			dev = usbi_alloc_device(ctx, session_id);
-			if (dev == NULL)
-				return (LIBUSB_ERROR_NO_MEM);
-
-			dev->bus_number = di.udi_bus;
-			dev->device_address = di.udi_addr;
-			dev->speed = di.udi_speed;
-
-			dpriv = (struct device_priv *)dev->os_priv;
-			strlcpy(dpriv->devnode, devnode, sizeof(devnode));
-			dpriv->fd = -1;
-
-			if (ioctl(fd, USB_GET_DEVICE_DESC, &dpriv->ddesc) < 0) {
-				err = errno;
-				goto error;
+		bzero(devices, sizeof(devices));
+		for (addr = 1; addr < USB_MAX_DEVICES; addr++) {
+			if (devices[addr])
+				continue;
+
+			di.udi_addr = addr;
+			if (ioctl(fd, USB_DEVICEINFO, &di) < 0)
+				continue;
+
+			/*
+			 * XXX If ugen(4) is attached to the USB device
+			 * it will be used.
+			 */
+			udevname = NULL;
+			for (j = 0; j < USB_MAX_DEVNAMES; j++)
+				if (!strncmp("ugen", di.udi_devnames[j], 4)) {
+					udevname = strdup(di.udi_devnames[j]);
+					break;
+				}
+
+			session_id = (di.udi_bus << 8 | di.udi_addr);
+			dev = usbi_get_device_by_session_id(ctx, session_id);
+
+			if (dev == NULL) {
+				dev = usbi_alloc_device(ctx, session_id);
+				if (dev == NULL) {
+					close(fd);
+					return (LIBUSB_ERROR_NO_MEM);
+				}
+
+				dev->bus_number = di.udi_bus;
+				dev->device_address = di.udi_addr;
+				dev->speed = di.udi_speed;
+
+				dpriv = (struct device_priv *)dev->os_priv;
+				dpriv->fd = -1;
+				dpriv->cdesc = NULL;
+				dpriv->devname = udevname;
+
+				dd.udd_bus = di.udi_bus;
+				dd.udd_addr = di.udi_addr;
+				if (ioctl(fd, USB_DEVICE_GET_DDESC, &dd) < 0) {
+					libusb_unref_device(dev);
+					continue;
+				}
+				dpriv->ddesc = dd.udd_desc;
+
+				if (_cache_active_config_descriptor(dev)) {
+					libusb_unref_device(dev);
+					continue;
+				}
+
+				if (usbi_sanitize_device(dev))
+					libusb_unref_device(dev);
 			}
 
-			dpriv->cdesc = NULL;
-			if (_cache_active_config_descriptor(dev, fd)) {
-				err = errno;
-				goto error;
+			ddd = discovered_devs_append(*discdevs, dev);
+			if (ddd == NULL) {
+				close(fd);
+				return (LIBUSB_ERROR_NO_MEM);
 			}
 
-			if ((err = usbi_sanitize_device(dev)))
-				goto error;
+			*discdevs = ddd;
+			devices[addr] = 1;
 		}
-		close(fd);
 
-		if (discovered_devs_append(*discdevs, dev) == NULL)
-			return (LIBUSB_ERROR_NO_MEM);
-
-		libusb_unref_device(dev);
+		close(fd);
 	}
 
 	return (LIBUSB_SUCCESS);
-
-error:
-	close(fd);
-	libusb_unref_device(dev);
-	return _errno_to_libusb(err);
 }
 
 int
@@ -211,15 +240,21 @@ obsd_open(struct libusb_device_handle *handle)
 {
 	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
 	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
+	char devnode[16];
 
-	dpriv->fd = open(dpriv->devnode, O_RDWR);
-	if (dpriv->fd < 0) {
-		dpriv->fd = open(dpriv->devnode, O_RDONLY);
+	if (dpriv->devname) {
+		/*
+		 * Only open ugen(4) attached devices read-write, all
+		 * read-only operations are done through the bus node.
+		 */
+		snprintf(devnode, sizeof(devnode), DEVPATH "%s.00",
+		    dpriv->devname);
+		dpriv->fd = open(devnode, O_RDWR);
 		if (dpriv->fd < 0)
 			return _errno_to_libusb(errno);
-	}
 
-	usbi_dbg("open %s: fd %d", dpriv->devnode, dpriv->fd);
+		usbi_dbg("open %s: fd %d", devnode, dpriv->fd);
+	}
 
 	if (pipe(hpriv->pipe) < 0)
 		return _errno_to_libusb(errno);
@@ -233,10 +268,12 @@ obsd_close(struct libusb_device_handle *handle)
 	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
 	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 
-	usbi_dbg("close: fd %d", dpriv->fd);
+	if (dpriv->devname) {
+		usbi_dbg("close: fd %d", dpriv->fd);
 
-	close(dpriv->fd);
-	dpriv->fd = -1;
+		close(dpriv->fd);
+		dpriv->fd = -1;
+	}
 
 	usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->pipe[0]);
 
@@ -264,9 +301,8 @@ obsd_get_active_config_descriptor(struct libusb_device *dev,
     unsigned char *buf, size_t len, int *host_endian)
 {
 	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
-	usb_config_descriptor_t *ucd;
+	usb_config_descriptor_t *ucd = (usb_config_descriptor_t *)dpriv->cdesc;
 
-	ucd = (usb_config_descriptor_t *) dpriv->cdesc;
 	len = MIN(len, UGETW(ucd->wTotalLength));
 
 	usbi_dbg("len %d", len);
@@ -275,58 +311,48 @@ obsd_get_active_config_descriptor(struct libusb_device *dev,
 
 	*host_endian = 0;
 
-	return len;
+	return (len);
 }
 
 int
 obsd_get_config_descriptor(struct libusb_device *dev, uint8_t idx,
     unsigned char *buf, size_t len, int *host_endian)
 {
-	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
-	struct usb_full_desc ufd;
+	struct usb_device_fdesc udf;
 	int fd, err;
 
-	usbi_dbg("index %d, len %d", idx, len);
+	if ((fd = _bus_open(dev->bus_number)) < 0)
+		return _errno_to_libusb(errno);
 
-	/* A config descriptor may be requested before opening the device */
-	if (dpriv->fd >= 0) {
-		fd = dpriv->fd;
-	} else {
-		fd = open(dpriv->devnode, O_RDONLY);
-		if (fd < 0)
-			return _errno_to_libusb(errno);
-	}
+	udf.udf_bus = dev->bus_number;
+	udf.udf_addr = dev->device_address;
+	udf.udf_config_index = idx;
+	udf.udf_size = len;
+	udf.udf_data = buf;
 
-	ufd.ufd_config_index = idx;
-	ufd.ufd_size = len;
-	ufd.ufd_data = buf;
+	usbi_dbg("index %d, len %d", udf.udf_config_index, len);
 
-	if ((ioctl(fd, USB_GET_FULL_DESC, &ufd)) < 0) {
+	if (ioctl(fd, USB_DEVICE_GET_FDESC, &udf) < 0) {
 		err = errno;
-		if (dpriv->fd < 0)
-			close(fd);
+		close(fd);
 		return _errno_to_libusb(err);
 	}
-
-	if (dpriv->fd < 0)
-		close(fd);
+	close(fd);
 
 	*host_endian = 0;
 
-	return len;
+	return (len);
 }
 
 int
 obsd_get_configuration(struct libusb_device_handle *handle, int *config)
 {
 	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
+	usb_config_descriptor_t *ucd = (usb_config_descriptor_t *)dpriv->cdesc;
 
-	usbi_dbg("");
+	*config = ucd->bConfigurationValue;
 
-	if (ioctl(dpriv->fd, USB_GET_CONFIG, config) < 0)
-		return _errno_to_libusb(errno);
-
-	usbi_dbg("configuration %d", *config);
+	usbi_dbg("bConfigurationValue %d", *config);
 
 	return (LIBUSB_SUCCESS);
 }
@@ -336,12 +362,15 @@ obsd_set_configuration(struct libusb_device_handle *handle, int config)
 {
 	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 
-	usbi_dbg("configuration %d", config);
+	if (dpriv->devname == NULL)
+		return (LIBUSB_ERROR_NOT_SUPPORTED);
+
+	usbi_dbg("bConfigurationValue %d", config);
 
 	if (ioctl(dpriv->fd, USB_SET_CONFIG, &config) < 0)
 		return _errno_to_libusb(errno);
 
-	return _cache_active_config_descriptor(handle->dev, dpriv->fd);
+	return _cache_active_config_descriptor(handle->dev);
 }
 
 int
@@ -376,6 +405,9 @@ obsd_set_interface_altsetting(struct libusb_device_handle *handle, int iface,
 	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 	struct usb_alt_interface intf;
 
+	if (dpriv->devname == NULL)
+		return (LIBUSB_ERROR_NOT_SUPPORTED);
+
 	usbi_dbg("iface %d, setting %d", iface, altsetting);
 
 	memset(&intf, 0, sizeof(intf));
@@ -392,19 +424,27 @@ obsd_set_interface_altsetting(struct libusb_device_handle *handle, int iface,
 int
 obsd_clear_halt(struct libusb_device_handle *handle, unsigned char endpoint)
 {
-	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 	struct usb_ctl_request req;
+	int fd, err;
+
+	if ((fd = _bus_open(handle->dev->bus_number)) < 0)
+		return _errno_to_libusb(errno);
 
 	usbi_dbg("");
 
+	req.ucr_addr = handle->dev->device_address;
 	req.ucr_request.bmRequestType = UT_WRITE_ENDPOINT;
 	req.ucr_request.bRequest = UR_CLEAR_FEATURE;
 	USETW(req.ucr_request.wValue, UF_ENDPOINT_HALT);
 	USETW(req.ucr_request.wIndex, endpoint);
 	USETW(req.ucr_request.wLength, 0);
 
-	if (ioctl(dpriv->fd, USB_DO_REQUEST, &req) < 0)
-		return _errno_to_libusb(errno);
+	if (ioctl(fd, USB_REQUEST, &req) < 0) {
+		err = errno;
+		close(fd);
+		return _errno_to_libusb(err);
+	}
+	close(fd);
 
 	return (LIBUSB_SUCCESS);
 }
@@ -425,6 +465,7 @@ obsd_destroy_device(struct libusb_device *dev)
 	usbi_dbg("");
 
 	free(dpriv->cdesc);
+	free(dpriv->devname);
 }
 
 int
@@ -564,6 +605,8 @@ obsd_clock_gettime(int clkid, struct timespec *tp)
 int
 _errno_to_libusb(int err)
 {
+	usbi_dbg("error: %s (%d)", strerror(err), err);
+
 	switch (err) {
 	case EIO:
 		return (LIBUSB_ERROR_IO);
@@ -573,52 +616,64 @@ _errno_to_libusb(int err)
 		return (LIBUSB_ERROR_NO_DEVICE);
 	case ENOMEM:
 		return (LIBUSB_ERROR_NO_MEM);
+	case ETIMEDOUT:
+		return (LIBUSB_ERROR_TIMEOUT);
 	}
 
-	usbi_dbg("error: %s", strerror(err));
-
 	return (LIBUSB_ERROR_OTHER);
 }
 
 int
-_cache_active_config_descriptor(struct libusb_device *dev, int fd)
+_cache_active_config_descriptor(struct libusb_device *dev)
 {
 	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
-	struct usb_config_desc ucd;
-	struct usb_full_desc ufd;
+	struct usb_device_cdesc udc;
+	struct usb_device_fdesc udf;
 	unsigned char* buf;
-	int len;
+	int fd, len, err;
 
-	usbi_dbg("fd %d", fd);
+	if ((fd = _bus_open(dev->bus_number)) < 0)
+		return _errno_to_libusb(errno);
 
-	ucd.ucd_config_index = USB_CURRENT_CONFIG_INDEX;
+	usbi_dbg("fd %d, addr %d", fd, dev->device_address);
 
-	if ((ioctl(fd, USB_GET_CONFIG_DESC, &ucd)) < 0)
+	udc.udc_bus = dev->bus_number;
+	udc.udc_addr = dev->device_address;
+	udc.udc_config_index = USB_CURRENT_CONFIG_INDEX;
+	if (ioctl(fd, USB_DEVICE_GET_CDESC, &udc) < 0) {
+		err = errno;
+		close(fd);
 		return _errno_to_libusb(errno);
+	}
 
-	usbi_dbg("active bLength %d", ucd.ucd_desc.bLength);
+	usbi_dbg("active bLength %d", udc.udc_desc.bLength);
 
-	len = UGETW(ucd.ucd_desc.wTotalLength);
+	len = UGETW(udc.udc_desc.wTotalLength);
 	buf = malloc(len);
 	if (buf == NULL)
 		return (LIBUSB_ERROR_NO_MEM);
 
-	ufd.ufd_config_index = ucd.ucd_config_index;
-	ufd.ufd_size = len;
-	ufd.ufd_data = buf;
+	udf.udf_bus = dev->bus_number;
+	udf.udf_addr = dev->device_address;
+	udf.udf_config_index = udc.udc_config_index;
+	udf.udf_size = len;
+	udf.udf_data = buf;
 
-	usbi_dbg("index %d, len %d", ufd.ufd_config_index, len);
+	usbi_dbg("index %d, len %d", udf.udf_config_index, len);
 
-	if ((ioctl(fd, USB_GET_FULL_DESC, &ufd)) < 0) {
+	if (ioctl(fd, USB_DEVICE_GET_FDESC, &udf) < 0) {
+		err = errno;
+		close(fd);
 		free(buf);
-		return _errno_to_libusb(errno);
+		return _errno_to_libusb(err);
 	}
+	close(fd);
 
 	if (dpriv->cdesc)
 		free(dpriv->cdesc);
 	dpriv->cdesc = buf;
 
-	return (0);
+	return (LIBUSB_SUCCESS);
 }
 
 int
@@ -633,12 +688,13 @@ _sync_control_transfer(struct usbi_transfer *itransfer)
 	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
 	setup = (struct libusb_control_setup *)transfer->buffer;
 
-	usbi_dbg("type %d request %d value %d index %d length %d timeout %d",
+	usbi_dbg("type %x request %x value %x index %d length %d timeout %d",
 	    setup->bmRequestType, setup->bRequest,
 	    libusb_le16_to_cpu(setup->wValue),
 	    libusb_le16_to_cpu(setup->wIndex),
 	    libusb_le16_to_cpu(setup->wLength), transfer->timeout);
 
+	req.ucr_addr = transfer->dev_handle->dev->device_address;
 	req.ucr_request.bmRequestType = setup->bmRequestType;
 	req.ucr_request.bRequest = setup->bRequest;
 	/* Don't use USETW, libusbx already deals with the endianness */
@@ -650,11 +706,30 @@ _sync_control_transfer(struct usbi_transfer *itransfer)
 	if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
 		req.ucr_flags = USBD_SHORT_XFER_OK;
 
-	if ((ioctl(dpriv->fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
-		return _errno_to_libusb(errno);
+	if (dpriv->devname == NULL) {
+		/*
+		 * XXX If the device is not attached to ugen(4) it is
+		 * XXX still possible to submit a control transfer but
+		 * XXX with the default timeout only.
+		 */
+		int fd, err;
 
-	if ((ioctl(dpriv->fd, USB_DO_REQUEST, &req)) < 0)
-		return _errno_to_libusb(errno);
+		if ((fd = _bus_open(transfer->dev_handle->dev->bus_number)) < 0)
+			return _errno_to_libusb(errno);
+
+		if ((ioctl(fd, USB_REQUEST, &req)) < 0) {
+			err = errno;
+			close(fd);
+			return _errno_to_libusb(err);
+		}
+		close(fd);
+	} else {
+		if ((ioctl(dpriv->fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
+			return _errno_to_libusb(errno);
+
+		if ((ioctl(dpriv->fd, USB_DO_REQUEST, &req)) < 0)
+			return _errno_to_libusb(errno);
+	}
 
 	itransfer->transferred = req.ucr_actlen;
 
@@ -668,7 +743,7 @@ _access_endpoint(struct libusb_transfer *transfer)
 {
 	struct handle_priv *hpriv;
 	struct device_priv *dpriv;
-	char *s, devnode[16];
+	char devnode[16];
 	int fd, endpt;
 	mode_t mode;
 
@@ -681,10 +756,9 @@ _access_endpoint(struct libusb_transfer *transfer)
 	usbi_dbg("endpoint %d mode %d", endpt, mode);
 
 	if (hpriv->endpoints[endpt] < 0) {
-		/* Pick the right node given the control one */
-		strlcpy(devnode, dpriv->devnode, sizeof(devnode));
-		s = strchr(devnode, '.');
-		snprintf(s, 4, ".%02d", endpt);
+		/* Pick the right endpoint node */
+		snprintf(devnode, sizeof(devnode), DEVPATH "%s.%02d",
+		    dpriv->devname, endpt);
 
 		/* We may need to read/write to the same endpoint later. */
 		if (((fd = open(devnode, O_RDWR)) < 0) && (errno == ENXIO))
@@ -701,9 +775,14 @@ int
 _sync_gen_transfer(struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer;
+	struct device_priv *dpriv;
 	int fd, nr = 1;
 
 	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
+
+	if (dpriv->devname == NULL)
+		return (LIBUSB_ERROR_NOT_SUPPORTED);
 
 	/*
 	 * Bulk, Interrupt or Isochronous transfer depends on the
@@ -732,3 +811,13 @@ _sync_gen_transfer(struct usbi_transfer *itransfer)
 
 	return (0);
 }
+
+int
+_bus_open(int number)
+{
+	char busnode[16];
+
+	snprintf(busnode, sizeof(busnode), USBDEV "%d", number);
+
+	return open(busnode, O_RDWR);
+}
diff --git a/third_party/libusb/src/libusb/os/poll_posix.h b/third_party/libusb/src/libusb/os/poll_posix.h
index 64c9bb7..5b4b2c9 100644
--- a/third_party/libusb/src/libusb/os/poll_posix.h
+++ b/third_party/libusb/src/libusb/os/poll_posix.h
@@ -1,19 +1,3 @@
-/*
- * 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 LIBUSB_POLL_POSIX_H
 #define LIBUSB_POLL_POSIX_H
 
diff --git a/third_party/libusb/src/libusb/os/poll_windows.c b/third_party/libusb/src/libusb/os/poll_windows.c
index 7ed19ba..abe8761 100644
--- a/third_party/libusb/src/libusb/os/poll_windows.c
+++ b/third_party/libusb/src/libusb/os/poll_windows.c
@@ -428,7 +428,7 @@ struct winfd fd_to_winfd(int fd)
 
 	CHECK_INIT_POLLING;
 
-	if (fd <= 0)
+	if (fd < 0)
 		return INVALID_WINFD;
 
 	for (i=0; i<MAX_FDS; i++) {
diff --git a/third_party/libusb/src/libusb/os/threads_posix.c b/third_party/libusb/src/libusb/os/threads_posix.c
index 46f6db7..cd985fa 100644
--- a/third_party/libusb/src/libusb/os/threads_posix.c
+++ b/third_party/libusb/src/libusb/os/threads_posix.c
@@ -58,7 +58,9 @@ finish:
 int usbi_get_tid(void)
 {
 	int ret = -1;
-#if defined(__linux__)
+#if defined(__ANDROID__)
+	ret = gettid();
+#elif defined(__linux__)
 	ret = syscall(SYS_gettid);
 #elif defined(__OpenBSD__)
 	/* The following only works with OpenBSD > 5.1 as it requires
diff --git a/third_party/libusb/src/libusb/os/wince_usb.c b/third_party/libusb/src/libusb/os/wince_usb.c
index e4a6633..90c129b 100644
--- a/third_party/libusb/src/libusb/os/wince_usb.c
+++ b/third_party/libusb/src/libusb/os/wince_usb.c
@@ -234,6 +234,12 @@ static int wince_init(struct libusb_context *ctx)
 			usbi_err(ctx, "Unable to create timer thread - aborting");
 			goto init_exit;
 		}
+
+		// Wait for timer thread to init before continuing.
+		if (WaitForSingleObject(timer_response, INFINITE) != WAIT_OBJECT_0) {
+			usbi_err(ctx, "Failed to wait for timer thread to become ready - aborting");
+			goto init_exit;
+		}
 	}
 	// At this stage, either we went through full init successfully, or didn't need to
 	r = LIBUSB_SUCCESS;
@@ -877,6 +883,11 @@ unsigned __stdcall wince_clock_gettime_threaded(void* param)
 		usbi_dbg("hires timer available (Frequency: %"PRIu64" Hz)", hires_frequency);
 	}
 
+	// Signal wince_init() that we're ready to service requests
+	if (ReleaseSemaphore(timer_response, 1, NULL) == 0) {
+		usbi_dbg("unable to release timer semaphore: %s", windows_error_str(0));
+	}
+
 	// Main loop - wait for requests
 	while (1) {
 		timer_index = WaitForMultipleObjects(2, timer_request, FALSE, INFINITE) - WAIT_OBJECT_0;
@@ -911,7 +922,7 @@ unsigned __stdcall wince_clock_gettime_threaded(void* param)
 			nb_responses = InterlockedExchange((LONG*)&request_count[0], 0);
 			if ( (nb_responses)
 			  && (ReleaseSemaphore(timer_response, nb_responses, NULL) == 0) ) {
-				usbi_dbg("unable to release timer semaphore %d: %s", windows_error_str(0));
+				usbi_dbg("unable to release timer semaphore: %s", windows_error_str(0));
 			}
 			continue;
 		case 1: // time to quit
diff --git a/third_party/libusb/src/libusb/os/windows_usb.c b/third_party/libusb/src/libusb/os/windows_usb.c
index 51ce55d..9ae11b1 100644
--- a/third_party/libusb/src/libusb/os/windows_usb.c
+++ b/third_party/libusb/src/libusb/os/windows_usb.c
@@ -886,6 +886,12 @@ static int windows_init(struct libusb_context *ctx)
 		}
 		SetThreadAffinityMask(timer_thread, 0);
 
+		// Wait for timer thread to init before continuing.
+		if (WaitForSingleObject(timer_response, INFINITE) != WAIT_OBJECT_0) {
+			usbi_err(ctx, "Failed to wait for timer thread to become ready - aborting");
+			goto init_exit;
+		}
+
 		// Create a hash table to store session ids. Second parameter is better if prime
 		htab_create(ctx, HTAB_SIZE);
 	}
@@ -1759,7 +1765,7 @@ static int windows_get_config_descriptor(struct libusb_device *dev, uint8_t conf
 	memcpy(buffer, priv->config_descriptor[config_index], size);
 	*host_endian = 0;
 
-	return size;
+	return (int)size;
 }
 
 /*
@@ -2173,6 +2179,11 @@ unsigned __stdcall windows_clock_gettime_threaded(void* param)
 		usbi_dbg("hires timer available (Frequency: %"PRIu64" Hz)", hires_frequency);
 	}
 
+	// Signal windows_init() that we're ready to service requests
+	if (ReleaseSemaphore(timer_response, 1, NULL) == 0) {
+		usbi_dbg("unable to release timer semaphore: %s", windows_error_str(0));
+	}
+
 	// Main loop - wait for requests
 	while (1) {
 		timer_index = WaitForMultipleObjects(2, timer_request, FALSE, INFINITE) - WAIT_OBJECT_0;
@@ -2207,7 +2218,7 @@ unsigned __stdcall windows_clock_gettime_threaded(void* param)
 			nb_responses = InterlockedExchange((LONG*)&request_count[0], 0);
 			if ( (nb_responses)
 			  && (ReleaseSemaphore(timer_response, nb_responses, NULL) == 0) ) {
-				usbi_dbg("unable to release timer semaphore %d: %s", windows_error_str(0));
+				usbi_dbg("unable to release timer semaphore: %s", windows_error_str(0));
 			}
 			continue;
 		case 1: // time to quit
diff --git a/third_party/libusb/src/libusb/strerror.c b/third_party/libusb/src/libusb/strerror.c
index a3c3afa..0212df8 100644
--- a/third_party/libusb/src/libusb/strerror.c
+++ b/third_party/libusb/src/libusb/strerror.c
@@ -53,7 +53,7 @@ static size_t usbi_locale = 0;
  *     }
  * };\endcode </li>
  * <li> Translate each of the English messages from the section you copied into your language </li>
- * <li> Save the file (in UTF-8 format) and send it to \c libusbx-devel@lists.sourceforge.net </li>
+ * <li> Save the file (in UTF-8 format) and send it to \c libusbx-devel\@lists.sourceforge.net </li>
  * </ol>
  */
 
diff --git a/third_party/libusb/src/libusb/version.h b/third_party/libusb/src/libusb/version.h
index fbb9f4c..f82e8c8 100644
--- a/third_party/libusb/src/libusb/version.h
+++ b/third_party/libusb/src/libusb/version.h
@@ -23,7 +23,7 @@
 #define LIBUSB_MINOR 0
 #endif
 #ifndef LIBUSB_MICRO
-#define LIBUSB_MICRO 16
+#define LIBUSB_MICRO 17
 #endif
 #ifndef LIBUSB_NANO
 #define LIBUSB_NANO 0
diff --git a/third_party/libusb/src/libusb/version_nano.h b/third_party/libusb/src/libusb/version_nano.h
index 522c6fd..1e3fc7b 100644
--- a/third_party/libusb/src/libusb/version_nano.h
+++ b/third_party/libusb/src/libusb/version_nano.h
@@ -14,4 +14,4 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#define LIBUSB_NANO 10774
+#define LIBUSB_NANO 10830