[alsa-devel] [Regression drm-tip] Internal audio device missing

[Takashi Iwai]

On Thu, 26 Dec 2019 15:41:34 +0100,
Paul Menzel wrote:
> 
> Dear Takashi,
> 
> 
> Am 26.12.19 um 11:03 schrieb Takashi Iwai:
> > On Thu, 26 Dec 2019 10:47:18 +0100, Paul Menzel wrote:
> 
> >> With
> >>
> >>      $ git describe --tags drm-tip/drm-tip
> >>      v5.5-rc3-1481-ga20d8cd6901a
> >>
> >> the internal audio device is not available, and just a dummy device.
> >>
> >> Running `alsa-info.sh` [1], the messages below are shown with the
> >> problematic Linux kernel.
> >>
> >>      alsactl: get_controls:567: snd_ctl_open error: Sound protocol is
> >> not compatible
> >>      cat: /tmp/alsa-info.ateDlDjrZX/alsactl.tmp: No such file or directory
> >
> > That's an unexpected side-effect of the recent protocol version bump
> > in sound.git for-next branch.  It seems that we can't change the minor
> > version unless we really want to break something.
> >
> > Below is the fix patch.  Please give it a try.
> 
> Thank you for the quick reply and fix.
> 
> > -- 8< --
> > From: Takashi Iwai <tiwai at suse.de>
> > Subject: [PATCH] ALSA: control: Fix incompatible protocol error
> >
> > The recent change to bump the ALSA control API protocol version from
> > 2.0.7 to 2.1.0 caused a regression on user-space; while the user-space
> > expects both the major and the minor versions to be identical with the
> > supported numbers, we changed the minor number from 0 to 1.
> >
> > For recovering from the incompatibility, this patch changes the
> > protocol version again to 2.0.8, which is compatible, but yet higher
> > than the original number 2.0.7, indicating that the protocol change.
> >
> > Fixes: bd3eb4e87eb3 ("ALSA: ctl: bump protocol version up to v2.1.0")
> > Reported-by: Paul Menzel <pmenzel at molgen.mpg.de>
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> >   include/uapi/sound/asound.h | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
> > index e36dadaf84ba..30ebb2a42983 100644
> > --- a/include/uapi/sound/asound.h
> > +++ b/include/uapi/sound/asound.h
> > @@ -936,7 +936,7 @@ struct snd_timer_tread {
> >    *                                                                          *
> >    ****************************************************************************/
> >   -#define SNDRV_CTL_VERSION		SNDRV_PROTOCOL_VERSION(2, 1,
> > 0)
> > +#define SNDRV_CTL_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 8)
> >     struct snd_ctl_card_info {
> >   	int card;			/* card number */
> >
> 
> Tested-by: Paul Menzel <pmenzel at molgen.mpg.de>
> 
> Are there CI systems, which should have caught this problem?
> 
> Which user-space component should forward this problem to the user
> (desktop environment displaying a warning)?

Unfortunately no -- I'd love to have it, though.
I usually test and push more carefully, but it was a bit rush before
the holidays :)

Now merged and pushed out.


thanks,

Takashi