Re: [PATCH v6 46/52] opp: Put interconnect paths outside of opp_table_lock

Dmitry Osipenko
2020-10-27T20:26:26Z

27.10.2020 08:10, Viresh Kumar пишет:
> On 26-10-20, 01:17, Dmitry Osipenko wrote:
>> This patch fixes lockup which happens when OPP table is released if
>> interconnect provider uses OPP in the icc_provider->set() callback
>> and bandwidth of the ICC path is set to 0 by the ICC core when path
>> is released. The icc_put() doesn't need the opp_table_lock protection,
>> hence let's move it outside of the lock in order to resolve the problem.
>>
>> In particular this fixes tegra-devfreq driver lockup on trying to unload
>> the driver module. The devfreq driver uses OPP-bandwidth API and its ICC
>> provider also uses OPP for DVFS, hence they both take same opp_table_lock
>> when OPP table of the devfreq is released.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
...
>
> Never make such _fixes_ part of such a big patchset. Always send them
> separately.

Perhaps it's not obvious from the commit description that this patch
doesn't fix any known problems of the current mainline kernel and it's
needed only for the new patches.

> Having said that, I already have a patch with me which shall fix it for you as
> well:

I see that yours fix is already applied, thanks!