[PATCH][Natty SRU] UBUNTU: SAUCE: uvcvideo: add SetInterface(0) in .reset_resume handler

[Tim Gardner]

On 07/25/2011 09:39 PM, Ming Lei wrote:
>  From 2f485a24a5732b980f2d1c7097469f07cb848c70 Mon Sep 17 00:00:00 2001
> From: Ming Lei<ming.lei at canonical.com>
> Date: Sat, 16 Jul 2011 11:29:45 +0800
> Subject: [PATCH][Natty SRU] UBUNTU: SAUCE: uvcvideo: add SetInterface(0) in .reset_resume handler
>
> As commented in uvc_video_init,
>
> 	/* Alternate setting 0 should be the default, yet the XBox Live Vision
> 	 * Cam (and possibly other devices) crash or otherwise misbehave if
> 	 * they don't receive a SET_INTERFACE request before any other video
> 	 * control request.
> 	 */
>
> so it does make sense to add the SetInterface(0) in .reset_resume
> handler so that this kind of devices can work well if they are reseted
> during resume from system or runtime suspend.
>
> We have found, without the patch, Microdia camera(0c45:6437) can't send
> stream data any longer after it is reseted during resume from
> system suspend.
>
> SRU Justification:
>
> Impact:
> 	- without the patch, the Microdia camera(0c45:6437) can't
> 	work after system resume
>
> Fix:
>          - After applying the patch, the camera can work well after
> 	system resume
>
> BugLink: http://bugs.launchpad.net/bugs/733509
>
> upstream discusstion:  http://marc.info/?t=131037773100002&r=1&w=2
>
> Signed-off-by: Ming Lei<ming.lei at canonical.com>
> Cc: Jeremy Kerr<jeremy.kerr at canonical.com>
> ---
> BTW: The patch will enter 3.1-rc later, not sure how Oneiric will merge
> the patch.
> ---
>   drivers/media/video/uvc/uvc_driver.c |   14 +++++++++++++-
>   1 files changed, 13 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
> index b6eae48..41c6d1a 100644
> --- a/drivers/media/video/uvc/uvc_driver.c
> +++ b/drivers/media/video/uvc/uvc_driver.c
> @@ -1959,8 +1959,20 @@ static int __uvc_resume(struct usb_interface *intf, int reset)
>   	}
>
>   	list_for_each_entry(stream,&dev->streams, list) {
> -		if (stream->intf == intf)
> +		if (stream->intf == intf) {
> +			/*
> +			 * After usb bus reset, some devices may
> +			 * misbehave if SetInterface(0) is not done, for
> +			 * example, Microdia camera(0c45:6437) will stop
> +			 * sending streaming data. Looks like XBox Live
> +			 * Vision Cam needs it too, as commented in
> +			 * uvc_video_init.
> +			 */
> +			if (reset)
> +				usb_set_interface(stream->dev->udev,
> +					stream->intfnum, 0);
>   			return uvc_video_resume(stream);
> +		}
>   	}
>
>   	uvc_trace(UVC_TRACE_SUSPEND, "Resume: video streaming USB interface "

Its best if you remind us when its been merged in Linus' tree so we can 
just cherry-pick it in its final form.

rtg
-- 
Tim Gardner tim.gardner at canonical.com