[meta-freescale] Audio glitch with SGTL5000

[Fabio Estevam]

On Wed, Jan 21, 2015 at 12:30 AM, Nikolay Dimitrov <picmaster at mail.bg> wrote:
> Hi Fabio,
>
>
> On 01/21/2015 02:50 AM, Fabio Estevam wrote:
>>
>> Hi Nikolay,
>>
>> On Tue, Jan 20, 2015 at 10:34 PM, Nikolay Dimitrov <picmaster at mail.bg>
>> wrote:
>>
>>> I tried to reproduce the issue also with the integrated headphone amp,
>>> just to find out that my board design has an issue (oops!) - the
>>> headphones' ground is connected to the power supply ground instead of
>>> the virtual ground, so I can't test the VAG ramp fix this way. So I can
>>> only speculate that you tested your fix on a properly wired headphone
>>> output, and that's where it worked OK.
>>
>>
>> I tested on headphone output on a mx28evk.
>>
>> Here is a better link to the patch:
>>
>> https://git.kernel.org/cgit/linux/kernel/git/broonie/sound.git/patch/sound/soc/codecs/sgtl5000.c?id=c251ea7bd7a04f1f2575467e0de76e803cf59149
>>
>> The previous one only showed the change to sgtl5000.c.
>
>
> Thanks. But now I don't understand the logic of this patch. Here's the
> prototype of the helper function:
>
> int snd_soc_update_bits(struct snd_soc_codec *codec, unsigned int reg,
> unsigned int mask, unsigned int value);
>
> 3rd argument is a mask, and you're passing there SGTL5000_SMALL_POP, which
> is now 0.

Yes, you are right. It seems I cleared the bit instead of setting it.
I will retest on my boards.

>
>> Does the problem also happens on 3.19-rc5?
>
>
> Can't use mainline for this specific project, as I need VPU support.

Understood, but for debugging this sgtl5000 issue it would be easier
to use mainline and start a thread at alsa-devel.

Regards,

Fabio Estevam