4 files changed, 65 insertions, 6 deletions

diff --git a/linux/drivers/media/video/uvc/uvc_ctrl.c b/linux/drivers/media/video/uvc/uvc_ctrl.c
index 9de8a1db5..01c72935d 100644
--- a/linux/drivers/media/video/uvc/uvc_ctrl.c
+++ b/linux/drivers/media/video/uvc/uvc_ctrl.c
@@ -545,11 +545,16 @@ static inline __u8 *uvc_ctrl_data(struct uvc_control *ctrl, int id)
 	return ctrl->data + id * ctrl->info->size;
 }
 
-static inline int uvc_get_bit(const __u8 *data, int bit)
+static inline int uvc_test_bit(const __u8 *data, int bit)
 {
 	return (data[bit >> 3] >> (bit & 7)) & 1;
 }
 
+static inline void uvc_clear_bit(__u8 *data, int bit)
+{
+	data[bit >> 3] &= ~(1 << (bit & 7));
+}
+
 /* Extract the bit string specified by mapping->offset and mapping->size
  * from the little-endian data stored at 'data' and return the result as
  * a signed 32bit integer. Sign extension will be performed if the mapping
@@ -1308,6 +1313,51 @@ end:
 }
 
 /*
+ * Prune an entity of its bogus controls. This currently includes processing
+ * unit auto controls for which no corresponding manual control is available.
+ * Such auto controls make little sense if any, and are known to crash at
+ * least the SiGma Micro webcam.
+ */
+static void
+uvc_ctrl_prune_entity(struct uvc_entity *entity)
+{
+	static const struct {
+		u8 idx_manual;
+		u8 idx_auto;
+	} blacklist[] = {
+		{ 2, 11 }, /* Hue */
+		{ 6, 12 }, /* White Balance Temperature */
+		{ 7, 13 }, /* White Balance Component */
+	};
+
+	u8 *controls;
+	unsigned int size;
+	unsigned int i;
+
+	if (UVC_ENTITY_TYPE(entity) != VC_PROCESSING_UNIT)
+		return;
+
+	controls = entity->processing.bmControls;
+	size = entity->processing.bControlSize;
+
+	for (i = 0; i < ARRAY_SIZE(blacklist); ++i) {
+		if (blacklist[i].idx_auto >= 8 * size ||
+		    blacklist[i].idx_manual >= 8 * size)
+			continue;
+
+		if (!uvc_test_bit(controls, blacklist[i].idx_auto) ||
+		     uvc_test_bit(controls, blacklist[i].idx_manual))
+			continue;
+
+		uvc_trace(UVC_TRACE_CONTROL, "Auto control %u/%u has no "
+			"matching manual control, removing it.\n", entity->id,
+			blacklist[i].idx_auto);
+
+		uvc_clear_bit(controls, blacklist[i].idx_auto);
+	}
+}
+
+/*
  * Initialize device controls.
  */
 int uvc_ctrl_init_device(struct uvc_device *dev)
@@ -1333,6 +1383,9 @@ int uvc_ctrl_init_device(struct uvc_device *dev)
 			bControlSize = entity->camera.bControlSize;
 		}
 
+		if (dev->quirks & UVC_QUIRK_PRUNE_CONTROLS)
+			uvc_ctrl_prune_entity(entity);
+
 		for (i = 0; i < bControlSize; ++i)
 			ncontrols += hweight8(bmControls[i]);
 
@@ -1347,7 +1400,7 @@ int uvc_ctrl_init_device(struct uvc_device *dev)
 
 		ctrl = entity->controls;
 		for (i = 0; i < bControlSize * 8; ++i) {
-			if (uvc_get_bit(bmControls, i) == 0)
+			if (uvc_test_bit(bmControls, i) == 0)
 				continue;
 
 			ctrl->entity = entity;
diff --git a/linux/drivers/media/video/uvc/uvc_driver.c b/linux/drivers/media/video/uvc/uvc_driver.c
index 0a0ef6611..343792f0f 100644
--- a/linux/drivers/media/video/uvc/uvc_driver.c
+++ b/linux/drivers/media/video/uvc/uvc_driver.c
@@ -44,6 +44,7 @@
 #define DRIVER_VERSION		"v0.1.0"
 #endif
 
+unsigned int uvc_no_drop_param;
 static unsigned int uvc_quirks_param;
 unsigned int uvc_trace_param;
 
@@ -1895,7 +1896,8 @@ static struct usb_device_id uvc_ids[] = {
 	  .bInterfaceSubClass	= 1,
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= UVC_QUIRK_PROBE_MINMAX
-				| UVC_QUIRK_IGNORE_SELECTOR_UNIT},
+				| UVC_QUIRK_IGNORE_SELECTOR_UNIT
+				| UVC_QUIRK_PRUNE_CONTROLS },
 	/* Generic USB Video Class */
 	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },
 	{}
@@ -1945,6 +1947,8 @@ static void __exit uvc_cleanup(void)
 module_init(uvc_init);
 module_exit(uvc_cleanup);
 
+module_param_named(nodrop, uvc_no_drop_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(nodrop, "Don't drop incomplete frames");
 module_param_named(quirks, uvc_quirks_param, uint, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(quirks, "Forced device quirks");
 module_param_named(trace, uvc_trace_param, uint, S_IRUGO|S_IWUSR);
diff --git a/linux/drivers/media/video/uvc/uvc_video.c b/linux/drivers/media/video/uvc/uvc_video.c
index 3be776a47..b19e91dd5 100644
--- a/linux/drivers/media/video/uvc/uvc_video.c
+++ b/linux/drivers/media/video/uvc/uvc_video.c
@@ -1007,7 +1007,8 @@ int uvc_video_enable(struct uvc_video_device *video, int enable)
 		return 0;
 	}
 
-	if (video->streaming->cur_format->flags & UVC_FMT_FLAG_COMPRESSED)
+	if ((video->streaming->cur_format->flags & UVC_FMT_FLAG_COMPRESSED) ||
+	    uvc_no_drop_param)
 		video->queue.flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
 	else
 		video->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE;
diff --git a/linux/drivers/media/video/uvc/uvcvideo.h b/linux/drivers/media/video/uvc/uvcvideo.h
index f95040380..a699c0bb1 100644
--- a/linux/drivers/media/video/uvc/uvcvideo.h
+++ b/linux/drivers/media/video/uvc/uvcvideo.h
@@ -4,8 +4,6 @@
 #include <linux/kernel.h>
 #include <linux/videodev2.h>
 
-#include "compat.h"
-
 /*
  * Dynamic controls
  */
@@ -69,6 +67,7 @@ struct uvc_xu_control {
 #ifdef __KERNEL__
 
 #include <linux/poll.h>
+#include "compat.h"
 
 /* --------------------------------------------------------------------------
  * UVC constants
@@ -317,6 +316,7 @@ struct uvc_xu_control {
 #define UVC_QUIRK_BUILTIN_ISIGHT	0x00000008
 #define UVC_QUIRK_STREAM_NO_FID		0x00000010
 #define UVC_QUIRK_IGNORE_SELECTOR_UNIT	0x00000020
+#define UVC_QUIRK_PRUNE_CONTROLS	0x00000040
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED		0x00000001
@@ -684,6 +684,7 @@ struct uvc_driver {
 #define UVC_WARN_MINMAX		0
 #define UVC_WARN_PROBE_DEF	1
 
+extern unsigned int uvc_no_drop_param;
 extern unsigned int uvc_trace_param;
 
 #define uvc_trace(flag, msg...) \