Run-time CODEC reset

Run-time CODEC reset

[Patrick Lai]

Hi,

I have a use case which requires CODEC to be reset at run-time. As
application exercises playback/capture through PCM device and mixer, my
understanding is that there is no interface for application to reset
CODEC through ALSA ASoC framework. CODEC driver would have to build
non-standard interface for this purpose. Is there precedence in any of
asoc CODEC driver which provides reset interface?

Thanks
Patrick

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Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

Re: Run-time CODEC reset

[Marek Vasut]

> Hi,
> 
> I have a use case which requires CODEC to be reset at run-time. As
> application exercises playback/capture through PCM device and mixer, my
> understanding is that there is no interface for application to reset
> CODEC through ALSA ASoC framework. CODEC driver would have to build
> non-standard interface for this purpose. Is there precedence in any of
> asoc CODEC driver which provides reset interface?

Why not describe the hardware / submit a patch to support the hardware first ? 
Then you can ask the developers for help. You can be helped more if you share 
your problematic code.

M

Re: Run-time CODEC reset

[Patrick Lai]

On 11/12/2011 10:29 PM, Marek Vasut wrote:
>> Hi,
>>
>> I have a use case which requires CODEC to be reset at run-time. As
>> application exercises playback/capture through PCM device and mixer, my
>> understanding is that there is no interface for application to reset
>> CODEC through ALSA ASoC framework. CODEC driver would have to build
>> non-standard interface for this purpose. Is there precedence in any of
>> asoc CODEC driver which provides reset interface?
>
> Why not describe the hardware / submit a patch to support the hardware first ?
> Then you can ask the developers for help. You can be helped more if you share
> your problematic code.

Actually, there is no bug. The use case is more to do with self test
mode. After running some audio tests to verify different audio paths
(i.e handset mode), self test application would like to trigger codec 
reset interface to restore CODEC default state. I was told that there 
are already ASOC CODEC drivers offering such interface. I want to see 
how this use case is handled by other CODEC drivers especially if 
command comes during playback/capture.

Thanks
Patrick


-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

Re: Run-time CODEC reset

[Mark Brown]

On Sun, Nov 13, 2011 at 08:52:37PM -0800, Patrick Lai wrote:
> On 11/12/2011 10:29 PM, Marek Vasut wrote:

> >Then you can ask the developers for help. You can be helped more if you share
> >your problematic code.

> Actually, there is no bug. The use case is more to do with self test
> mode. After running some audio tests to verify different audio paths
> (i.e handset mode), self test application would like to trigger
> codec reset interface to restore CODEC default state. I was told
> that there are already ASOC CODEC drivers offering such interface. I
> want to see how this use case is handled by other CODEC drivers
> especially if command comes during playback/capture.

There's no such interface.  This doesn't sound like something drivers
should support, it just sounds like your test application wants to save
the state before it starts and restore it afterwards, or the user should
use some external utility like alsactl to do so.  Why would an
application care if the codec hardware had been physically reset, that's
the sort of detail that the driver should be hiding?

Patrick, we routinely need to ask you for this sort of background
information in order to understand what it is you're actually trying to
do.  Normally you've already jumped very far into the implementation and
you don't mention the reasoning that you're relying on.