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

[Takashi Iwai]

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