Re: [PATCH] ALSA: usb-audio: Skip setting clock selector for single connections

[Alexander Tsoy <alexander@xxxxxxx>]

В Вт, 23/01/2024 в 15:14 +0100, Takashi Iwai пишет:
> > On Tue, 23 Jan 2024 14:46:35 +0100,
> > Alexander Tsoy wrote:
> > > > 
> > > > Since commit 086b957cc17f5 ("ALSA: usb-audio: Skip the clock
> > > > selector
> > > > inquiry for single connections") we are already skipping clock
> > > > selector
> > > > inquiry if only one clock source is connected, but we are still
> > > > sending
> > > > a set request. Lets skip that too.
> > > > 
> > > > This should fix errors when setting a sample rate on devices
> > > > that
> > > > don't
> > > > have any controls present within the clock selector. An example
> > > > of
> > > > such
> > > > device is the new revision of MOTU M Series (07fd:000b):
> > > > 
> > > >       AudioControl Interface Descriptor:
> > > >         bLength                 8
> > > >         bDescriptorType        36
> > > >         bDescriptorSubtype     11 (CLOCK_SELECTOR)
> > > >         bClockID                1
> > > >         bNrInPins               1
> > > >         baCSourceID(0)          2
> > > >         bmControls           0x00
> > > >         iClockSelector          0
> > > > 
> > > > Perhaps we also should check if clock selectors are readable
> > > > and
> > > > writeable
> > > > like we already do for clock sources, but this is out of scope
> > > > of
> > > > this
> > > > patch.
> > > > 
> > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=217601
> > > > Signed-off-by: Alexander Tsoy <alexander@xxxxxxx>
> > 
> > Thanks, applied.

It looks like this patch will bring back problems with Behringer mixers
[1]. So we probably should revert. The mentioned case with MOTU M
Series should be also covered by "Support read-only clock selector
control" commit.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=199327