From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Subject: Re: [PATCH] asoc,
	codec: Add SGTL5000 codec support to asoc
Date: Thu, 9 Dec 2010 12:15:14 +0000
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To: Zeng Zhaoming <zhaoming.zeng@freescale.com>
Cc: s.hauer@pengutronix.de, festevam@gmail.com, alsa-devel@alsa-project.org, arnaud.patard@rtp-net.org, lrg@slimlogic.co.uk
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On Thu, Dec 09, 2010 at 03:22:35AM +0800, Zeng Zhaoming wrote:
> On Wed 2010-12-08 05:11:55, Mark Brown wrote:
> > On Wed, Dec 08, 2010 at 10:06:29AM +0800, zhaoming.zeng@freescale.com

> > > +	sgtl5000_set_bias_level(codec, codec->suspend_bias_level);

> > The CODEC will never be in any state above STANDBY at suspend.

> Is there any documentation describe the state machine? 

Not outside the source code.

> > > +	msleep(1);

> > This delay looks like it's in the wrong place?

> The SGTL5000 has an internal reset that is deasserted 8 SYS_MCLK cycles after 
> all power rails have been brought up. After this time communication can start.
> 
> So I think delay 1ms is safe for the next operations.

It needs to be tied much more clearly to the enables, then - that's not
clear at the minute, especially given that there's no code in the same
function that interacts with the hardware.