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Date: Mon, 11 Jan 2016 15:10:20 +0100
From: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
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To: Mark Brown <broonie@kernel.org>, Fabio Estevam <festevam@gmail.com>
CC: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
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 "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
 linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/3] ASoC: fsl_ssi: remove register defaults
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On 11.01.2016 15:00, Mark Brown wrote:
> On Mon, Jan 11, 2016 at 10:10:56AM -0200, Fabio Estevam wrote:
>> On Mon, Jan 11, 2016 at 10:04 AM, Fabio Estevam <festevam@gmail.com> wrote:
> 
>>> [    2.526984] ------------[ cut here ]------------
>>> [    2.531632] WARNING: CPU: 1 PID: 1 at kernel/locking/lockdep.c:2755
>>> lockdep_trace_alloc+0xf4/0x124()
> 
>> This fixes the warning:
> 
>> --- a/sound/soc/fsl/fsl_ssi.c
>> +++ b/sound/soc/fsl/fsl_ssi.c
>> @@ -180,7 +180,6 @@ static const struct regmap_config fsl_ssi_regconfig = {
>>         .volatile_reg = fsl_ssi_volatile_reg,
>>         .precious_reg = fsl_ssi_precious_reg,
>>         .writeable_reg = fsl_ssi_writeable_reg,
>> -       .cache_type = REGCACHE_RBTREE,
>>  };
> 
>> Is this the correct fix?
> 
> I suspect not, it looks like the driver is using the cache for
> suspend/resume handling.  I've dropped the patch for now.  Either the
> driver should explicitly write to the relevant registers outside of
> interrupt context to ensure the cache entry exists or it should keep the
> defaults and explicitly write them to hardware at startup to ensure
> sync (the former is more likely to be safe).

Is it acceptable to switch it to flat cache instead to not keep the register
defaults in driver?

Maciej