V4L/DVB (13155): uvcvideo: Add a module parameter to set the streamin…

…g control timeout

The default streaming control timeout was found by Ondrej Zary to be too low
for some Logitech webcams. With kernel 2.6.22 and newer they would timeout
during initialization unles the audio function was initialized before the
video function.

Add a module parameter to set the streaming control timeout and increase the
default value from 1000ms to 3000ms to fix the above problem.

Thanks to Ondrej Zary for investigating the issue and providing an initial
patch.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/uvc/uvc_driver.c

@@ -46,6 +46,7 @@
 unsigned int uvc_no_drop_param;
 static unsigned int uvc_quirks_param;
 unsigned int uvc_trace_param;
+unsigned int uvc_timeout_param = UVC_CTRL_STREAMING_TIMEOUT;
 
 /* ------------------------------------------------------------------------
  * Video formats
@@ -2195,6 +2196,8 @@ 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);
 MODULE_PARM_DESC(trace, "Trace level bitmask");
+module_param_named(timeout, uvc_timeout_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(timeout, "Streaming control requests timeout");
 
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);

drivers/media/video/uvc/uvc_video.c

@@ -135,7 +135,7 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 
 	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
 		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
-		size, UVC_CTRL_STREAMING_TIMEOUT);
+		size, uvc_timeout_param);
 
 	if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
 		/* Some cameras, mostly based on Bison Electronics chipsets,
@@ -239,7 +239,7 @@ static int uvc_set_video_ctrl(struct uvc_streaming *stream,
 
 	ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
 		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
-		size, UVC_CTRL_STREAMING_TIMEOUT);
+		size, uvc_timeout_param);
 	if (ret != size) {
 		uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
 			"%d (exp. %u).\n", probe ? "probe" : "commit",

drivers/media/video/uvc/uvcvideo.h

@@ -148,7 +148,7 @@ struct uvc_xu_control {
 #define UVC_MAX_STATUS_SIZE	16
 
 #define UVC_CTRL_CONTROL_TIMEOUT	300
-#define UVC_CTRL_STREAMING_TIMEOUT	1000
+#define UVC_CTRL_STREAMING_TIMEOUT	3000
 
 /* Devices quirks */
 #define UVC_QUIRK_STATUS_INTERVAL	0x00000001
@@ -538,6 +538,7 @@ struct uvc_driver {
 
 extern unsigned int uvc_no_drop_param;
 extern unsigned int uvc_trace_param;
+extern unsigned int uvc_timeout_param;
 
 #define uvc_trace(flag, msg...) \
 	do { \