[alsa-devel] [PATCH -next] ASoC: pandora: Add DAC regulator support

Grazvydas Ignotas notasas at gmail.com
Sat Feb 6 18:33:08 CET 2010

On Fri, Feb 5, 2010 at 7:20 PM, Mark Brown
<broonie at opensource.wolfsonmicro.com> wrote:
> On Fri, Feb 05, 2010 at 04:29:53PM +0200, Grazvydas Ignotas wrote:
>> Uh, I meant "no audible improvement". However I've just checked the
>> DAC datasheet again and it requires 1ms delay between turning on/off
>> the supply and switching /PD pin (connected to
>> OMAP3_PANDORA_DAC_POWER_GPIO). Even though I hear no difference,
>> adding the delays back just in case. Updated patch attached.
> Which step of the powerup is the one that generates the pop?  As Liam
> says if you can mute the DAC while powering up might help if that's
> possible, though looking I don't think it is.

It's on powerdown, there is a faint pop. It appears its the amp (final
part in the path), I tried to toggle it while playing /dev/zero
manually and it always pops on powerdown. On powerup there is a small
sound cutoff too, probably because of amp capacitors charging, but we
decided to leave it instead of halting every sound playing program
until the amp gets ready.

>> From 72cdf36e432a9929baff8841df979f13492dc813 Mon Sep 17 00:00:00 2001
>> From: Grazvydas Ignotas <notasas at gmail.com>
>> Date: Fri, 5 Feb 2010 12:57:37 +0200
>> Subject: [PATCH -next] ASoC: pandora: Add DAC regulator support
> Please don't append patches to messages like this, it makes them harder
> to apply since the e-mail text ends up as part of the commit message as
> does the patch header.
> Applied, thanks.

noted, thanks.

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