[PATCH 1/3] clk: exynos-audss: Keep the parent of mout_audss always enabled

Doug Anderson dianders at google.com
Tue Jun 24 15:59:17 PDT 2014


Tushar,

On Thu, Jun 12, 2014 at 12:40 AM, Tushar Behera <tushar.b at samsung.com> wrote:
> On Wed, Jun 11, 2014 at 10:20 PM, Kevin Hilman <khilman at linaro.org> wrote:
>> Tushar Behera <tushar.b at samsung.com> writes:
>>
>>> When the output clock of AUDSS mux is disabled, we are getting kernel
>>> oops while doing a clk_get() on other clocks provided by AUDSS.
>>>
>>> Though user manual doesn't specify this dependency, we came across
>>> this issue while disabling the parent of AUDSS mux clocks.
>>>
>>> Keeping the parents of AUDSS mux always enabled fixes this issue.
>>
>> While this patch works (and fixes the boot problem for me), it seems
>> like it's papering over the real problem.
>>
>
> Thanks for testing.
>
>> Seems like the right fix is actually modelling the clocks properly so
>> that enabling a child clock ensures that the parent is also enabled.
>>
>
> Patch 2/3 was to ensure we have proper clock tree defined for
> Exynos5420. While testing with audio disabled, that patch alone fixed
> the issue. But when audio was enabled (and hence I2S0 was trying to
> access the clocks), we got some kernel oops during late booting, hence
> I came up this solution.
>
> The solution might be a little half-baked because of the urgency to
> push the fix, but will try to dig more into the issue on Monday when I
> resume office.

Which Monday were you referring to?  ;)

...but in all seriousness do you have an official status update on
this patch?  It seems as if it's not needed and all you need is
<https://patchwork.kernel.org/patch/4333581/>, but it would be nice to
get an official confirmation.

Thanks!

-Doug



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