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

[Ming Lei]

On Thu, Sep 29, 2011 at 1:34 PM, Brad Figg <brad.figg at canonical.com> wrote:
> On 07/25/2011 08:39 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
>> "
>
> Please note that the buglink referred to in the commit is a Private bug.

We has a public butlink for it already:

           https://bugs.launchpad.net/bugs/816484

thanks,
--
Ming Lei