Re: [PATCH v2 0/5] Cpufreq frequency serialization fixes

From: Srivatsa S. Bhat
Date: Tue Apr 29 2014 - 02:00:32 EST


On 04/29/2014 05:17 AM, Rafael J. Wysocki wrote:
> On Tuesday, April 29, 2014 12:23:54 AM Srivatsa S. Bhat wrote:
>>
>> Hi,
>>
>> Meelis Roos reported hangs during boot in the longhaul cpufreq driver, after
>> commit 12478cf0c55 (cpufreq: Make sure frequency transitions are serialized).
>> The root-cause of this issue is the extra invocation of the
>> cpufreq_freq_transition_begin() and cpufreq_freq_transition_end() APIs in the
>> longhaul driver. I found similar issues in the powernow-k6 and powernow-k7
>> drivers as well. This patchset fixes the issue in all the 3 drivers and also
>> adds a debug infrastructure to catch such issues easily.
>>
>> Patches 1-4 fix the regression in longhaul, powernow-k6 and powernow-k7
>> drivers. (Patch 2 fixes a different bug in powernow-k6, and it is kept as a
>> separate patch instead of merging it with patch 3, because I felt that it was
>> a bit subtle and needed attention in a separate patch).
>>
>> Patch 5 adds a debug infrastructure to the cpufreq core to catch such problems
>> more easily in the future.
>
> I've queued up patches [1-4/5] for 3.15, the last one I need to have another
> look at tomorrow.

Great! Thanks a lot!

>
> BTW, when you fix regressions, please always add a Fixes: tag to the changelog.
>

Oh, ok, will keep that in mind from next time. Thank you!

Regards,
Srivatsa S. Bhat

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/