[meta-freescale] Audio glitch with SGTL5000

[Nikolay Dimitrov]

Hi Fabio,

On 01/22/2015 02:00 AM, Fabio Estevam wrote:
> Hi Nikolay,
>
> On Wed, Jan 21, 2015 at 9:55 PM, Nikolay Dimitrov <picmaster at mail.bg> wrote:
>
>> Hehe, I'm not sure that you cleared the bit actually :). I think that
>> with mask 0 you're not writing to the I2C reg at all - you can check
>> the return value of snd_soc_update_bits(), should be 0 (no error, no
>> value changed). But would be great if you can also monitor the I2C bus
>> traffic to confirm whether you really write or not to this register.
>>
>> Can you try to change only the last argument and hear whether it makes
>> a difference, like this:
>>
>> snd_soc_update_bits(codec, SGTL5000_CHIP_REF_CTRL, 1, 1);
>> snd_soc_update_bits(codec, SGTL5000_CHIP_REF_CTRL, 1, 0);
>
> My tests show the following:
>
> - With SMALL_POP 0 (no click)
> - With SMALL_POP 1 (click)
>
> Yes, this sounds strange. With my patch applied we end up with
> SMALL_POP 0 (default value) and I don't hear the click on mx28evk nor
> mx53qsb.

Well, it's possible that there's a mistake in the datasheet. If you have 
access to some engineers who worked on the audio codec, could be a good 
idea to check with them about this SMALL_POP bit.

So, it looks like I'll have to stick with my ugly fix for a while. I'll 
share with the ML if I find a solution for my issue.

Kind regards,
Nikolay