[alsa-devel] [PATCH] ALSA: usb-audio: Fix UAC2 get_ctl request with a RANGE attribute

[Takashi Iwai]

On Mon, 12 Feb 2018 20:32:53 +0100,
Kirill Marinushkin wrote:
> 
> Hello maintainers of <stable at vger.kernel.org>,
> 
> 
> As discussed earlier in this thread, I propose this patch to stable.
> 
> It fixes the issue, which exists since v2.6.34.

It's already marked in the applied patch, so you don't need to ping
stable kernel guys.


thanks,

Takashi

> 
> 
> Best Regards,
> 
> Kirill
> 
> On 02/12/18 09:08, Takashi Iwai wrote:
> > On Thu, 08 Feb 2018 07:21:36 +0100,
> > Kirill Marinushkin wrote:
> >> On 02/07/18 06:45, Takashi Iwai wrote:
> >>> On Mon, 29 Jan 2018 06:37:55 +0100,
> >>> Kirill Marinushkin wrote:
> >>>> The layout of the UAC2 Control request and response varies depending on
> >>>> the request type. With the current implementation, only the Layout 2
> >>>> Parameter Block (with the 2-byte sized RANGE attribute) is handled
> >>>> properly. For the Control requests with the 1-byte sized RANGE attribute
> >>>> (Bass Control, Mid Control, Tremble Control), the response is parsed
> >>>> incorrectly.
> >>>>
> >>>> This commit:
> >>>> * fixes the wLength field value in the request
> >>>> * fixes parsing the range values from the response
> >>>>
> >>>> Fixes: 23caaf19b11e ("ALSA: usb-mixer: Add support for Audio Class v2.0")
> >>>> Signed-off-by: Kirill Marinushkin <k.marinushkin at gmail.com>
> >>>> Cc: Jaroslav Kysela <perex at perex.cz>
> >>>> Cc: Takashi Iwai <tiwai at suse.com>
> >>>> Cc: Jaejoong Kim <climbbb.kim at gmail.com>
> >>>> Cc: Bhumika Goyal <bhumirks at gmail.com>
> >>>> Cc: Stephen Barber <smbarber at chromium.org>
> >>>> Cc: Julian Scheel <julian at jusst.de>
> >>>> Cc: alsa-devel at alsa-project.org
> >>>> Cc: linux-kernel at vger.kernel.org
> >>> Sorry for the late reply, as I've been (and still) off.
> >>>
> >>> Does this bug actually hit on any real devices, or is it only a
> >>> logical error so far?  In the former case, a Cc to stable is
> >>> mandatory.
> >>>
> >>> In anyway, I'll review and merge it properly once after I back to
> >>> work.
> >>>
> >>>
> >>> thanks,
> >>>
> >>> Takashi
> >> Hello Takashi,
> >>
> >> Thank you for your answer. I will wait until you are back to work, don't 
> >> worry about the late replies.
> >>
> >> I did not hit the issue on a real device.
> >>
> >> During my UAC2 experiments, I reproduced this issue on the development 
> >> board, and then tested my solution on it.
> > OK, if it happened on a development system, it's a real issue, and we
> > should put Cc to stable.  Now I applied the patch.
> >
> > Thanks!
> >
> >
> > Takashi
>