Re: [RFC PATCH 2/6] ASoC: sgtl5000: write all default registers

[Eric Nelson <eric.nelson@boundarydevices.com>]

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Hi Mark,

On 03/06/2015 01:14 PM, Mark Brown wrote:
> On Thu, Feb 26, 2015 at 03:54:29PM -0700, Eric Nelson wrote:
>> If an error occurs writing defaults, produce an error message
>> but continue writing other registers. The failure of a single
>> write should not cause catastrophic device failure.
>> 
>> In at least one occurrence, I2C writes of CHIP_ANA_POWER was
>> nacked, though continuing allowed the device to operate
>> properly.
> 
> I'm a bit nervous about this.  Generally problems physically
> writing to the device are pretty bad and lead to followon hard to
> debug problems as the chip state drifts from the state the software
> thinks it has.  If this is a good idea I'd really like to see more
> analysis as to why this is expected to happen and why it's OK.
> 

I included this patch in the set because I found that the driver
would fail through a soft re-boot until I found the dependencies
of CHIP_CLK_CTRL and LINREG_CTRL in setting the initial value for
ANA_POWER.

By ignoring the failed register write, I found that I had functioning
audio.

Which begs the question: should we force complete failure on what may
be an intermittent problem.

My preference is no.

This is really un-related to the rest of the patch set.

Regards,


Eric
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