[alsa-devel] [PATCH v4 2/5] ASoC: Move standard kcontrol helpers to the component level

[Lars-Peter Clausen]

On 05/09/2014 05:00 PM, Shawn Guo wrote:
> Hi Lars,
>
> On Tue, Apr 22, 2014 at 01:23:14PM +0200, Lars-Peter Clausen wrote:
>> After moving the IO layer inside ASoC to the component level we can now easily
>> move the standard control helpers also to the component level. This allows to
>> reuse the same standard helper control implementations for other components.
>>
>> Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
>
> I'm running next-20140508 on imx6q-sabresd board and seeing repeated
> 'amixer: Mixer hw:0 load error: Device or resource busy' message with
> Debian wheezy rootfs.  The git bisect points me to this patch.
>
> == message output before this patch ==
>
> [....] Setting up ALSA...warning: 'alsactl restore' failed with error message 'Found hardware: "wm8962-audio" "" "" "" ""
> Hardware is initialized using a generic method
> [ ok tl: set_control:1328: failed to obtain info for control #117 (No such file or directory)'...done.
>
> == message output after this patch ==
>
> [....] Setting up ALSA...warning: 'alsactl restore' failed with error message 'Found hardware: "wm8962-audio" "" "" "" ""
> Hardware is initialized using a generic method
> alsactl: set_control:1328: failed to obtain info for control #117 (No such file or directory)'...amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> amixer: Mixer hw:0 load error: Device or resource busy
> done.
>
> Why do we start seeing such error message with your patch?  Is this
> a problem of rootfs or kernel?

The changes in the patch should mostly be transparent. But what changed is 
how error reporting is handled. If there is a error reading/writing a 
register in the kcontrol callbacks that error is passed on to userspace 
whereas previously it was silently ignored.

There is also the possibility that there is a bug somewhere in the patch 
causing this.

Does the board otherwise work fine?

I actually have the board here, if you tell me which devictree/defconfig I 
can use with an upstream kernel I can give things a try.

- Lars