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

[Paul Menzel]

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)?


Kind regards,

Paul