From 72362422f3a9cb66e26fa9f0d90d3ef5241e78ba Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sat, 14 Feb 2009 19:26:56 -0300 Subject: [PATCH] V4L/DVB (10650): uvcvideo: Initialize streaming parameters with the probe control value The UVC specification requires SET_CUR requests on the streaming commit control to use values retrieved from a successful GET_CUR request on the probe control. Initialize streaming parameters with the probe control current value to make sure the driver always complies. Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_video.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c index 7ebb89539c36..9139086f940a 100644 --- a/drivers/media/video/uvc/uvc_video.c +++ b/drivers/media/video/uvc/uvc_video.c @@ -1026,11 +1026,20 @@ int uvc_video_init(struct uvc_video_device *video) */ usb_set_interface(video->dev->udev, video->streaming->intfnum, 0); - /* Some webcams don't suport GET_DEF requests on the probe control. We - * fall back to GET_CUR if GET_DEF fails. + /* Set the streaming probe control with default streaming parameters + * retrieved from the device. Webcams that don't suport GET_DEF + * requests on the probe control will just keep their current streaming + * parameters. */ - if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 && - (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0) + if (uvc_get_video_ctrl(video, probe, 1, GET_DEF) == 0) + uvc_set_video_ctrl(video, probe, 1); + + /* Initialize the streaming parameters with the probe control current + * value. This makes sure SET_CUR requests on the streaming commit + * control will always use values retrieved from a successful GET_CUR + * request on the probe control, as required by the UVC specification. + */ + if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0) return ret; /* Check if the default format descriptor exists. Use the first -- 2.20.1