[meta-freescale] Audio glitch with SGTL5000

[Fabio Estevam]

On Thu, Jan 22, 2015 at 5:20 PM, Nikolay Dimitrov <picmaster at mail.bg> wrote:

> As we discussed with Fabio, when you define SGTL5000_SMALL_POP as 0, the
> following call...
>
> snd_soc_update_bits(codec, SGTL5000_CHIP_REF_CTRL, SGTL5000_SMALL_POP, 1);
>
> ...doesn't actually write to the I2C register, and leaves the default
> behavior, which is SMALL_POP = 1. And as Fabio noted, the audible behavior
> of this SMALL_POP bit is inverted as compared to the documentation, so
> SMALL_POP 0 should have the click audible, and SMALL_POP 1 should make it
> inaudible.
>
> For me personally the patch is misleading written this way - it looks like
> it's writing to the register, but neither this write is actually happening
> (you can sniff the I2C bus if you wish), and also this patch hides the issue
> with improperly documented SMALL_POP bit.

There was no intention to hide anything in that patch. The end result
(SMALL_POP cleared) silenced the click on my two boards, but I agree
that I would need to fix it properly as you pointed out.

This is off-topic here on a Yocto list though, so I suggest we move
such discussion to the alsa-devel list which is the appropriate place.