[alsa-devel] [PATCH 4/5] ASoC: fsl_ssi: use flat regmap cache

[Marek Vasut]

On 09/28/2016 02:04 AM, Maciej S. Szmigiero wrote:
> On 28.09.2016 01:29, Marek Vasut wrote:
>> On 09/28/2016 01:23 AM, Maciej S. Szmigiero wrote:
>>> On 26.09.2016 21:25, Marek Vasut wrote:
>>>> On 09/26/2016 09:13 PM, Mark Brown wrote:
>>> (..)
>>>>> So, can we get a clear decision on this after testing?  The discussion
>>>>> here and the discussion on IRC are a bit disjointed and I'd like to make
>>>>> sure we end up with something that definitely works.
>>>>>
>>>> I think 1,2,3,4 are certainly harmless. I think even 5 is harmless (at
>>>> least according to my testing on MX6Q and MX6SX, which is not the
>>>> greatest sample), but can be safely reverted if there are concerns.
>>>
>>> I've tested current sound/for-next on UDOO board and was able to reproduce
>>> a lockup on reloading fsl sound modules.
>>> The exact test was playing 30 second sound file and reloading modules in
>>> a loop.
>>> The lockup would happen sometimes almost immediately and sometimes after
>>> ~30 minutes of such testing.
>>>
>>> When I reverted commit 7de2763d9b325ee5e7e24ac513c93394406cfefa
>>> (that is, number 5) it seems that it no longer locks up.
>>
>> Do you have an explanation how would #5 cause this problem if it was
>> supposed to fix it ? ;-) Can you share the backtrace ?
> 
> I think the reason why it locks up is similar to previous case that it
> locked up in similar circumstances with hardcoded register defaults -
> there is some inconsistency between register value in cache and actual
> value in hardware which then gets (partially?) rewritten with cached
> value.
> But I don't know the exact problematic register.
> 
> It looks like the SoC just locks up after this error:
> ac97-codec ac97-codec.0: ASoC: codec DAI prepare error: -22

This looks like a different error, can you poke into this please ?

>>>> I also believe the following two patches should be backported for
>>>> 4.7 (they were part of tag 'regmap-fix-v4.8-rc5' of
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap):
>>>>
>>>> commit b2c7f5d9c939a37c1ce7f86a642de70e3033ee9e
>>>> Author: Maarten ter Huurne <maarten at treewalker.org>
>>>> Date:   Fri Jul 29 23:42:12 2016 +0200
>>>>
>>>>     regmap: cache: Fix num_reg_defaults computation from reg_defaults_raw
>>>>
>>>> commit 1bc8da4e143c0fd8807e061a66d91d5972601ab1
>>>> Author: Lars-Peter Clausen <lars at metafoo.de>
>>>> Date:   Thu Aug 4 17:22:16 2016 +0200
>>>>
>>>>     regmap: rbtree: Avoid overlapping nodes
>>>>
>>>
>>> I can see that
>>> "regmap: cache: Fix num_reg_defaults computation from reg_defaults_raw" is
>>> present in the tree that I have tested.
>>
>> And the rbtree patch is also present ?
> 
> Yes - I commented only on the first one since you said it would probably
> fix the rbtree crash (which I understand is the one which
> patch 5 was also trying to fix).

Seems like we have more problems then, sigh.

btw I also had to revert 5881826ded79cf3c3314ee2d84c3bfa94e111b42 on
latest next as it made my AC97 misbehave.

> Maciej
> 


-- 
Best regards,
Marek Vasut