Re: [PATCH V6 0/7] cpufreq: suspend early/resume late: dpm_{suspend|resume}()

Stephen Warren
2014-02-18T22:26:09Z

On 02/18/2014 03:36 PM, Rafael J. Wysocki wrote:
> On Tuesday, February 18, 2014 01:30:52 PM Stephen Warren wrote:
>> On 02/17/2014 02:25 AM, Viresh Kumar wrote:
>>> This patchset creates/calls cpufreq suspend/resume callbacks from dpm_{suspend|resume}()
>>> for handling suspend/resume of cpufreq governors and core.
>>>
>>> There are multiple problems that are fixed by this patch:
>>> - Nishanth Menon (TI) found an interesting problem on his platform, OMAP. His board
>>> wasn't working well with suspend/resume as calls for removing non-boot CPUs
>>> was turning out into a call to drivers ->target() which then tries to play
>>> with regulators. But regulators and their I2C bus were already suspended and
>>> this resulted in a failure. Many platforms have such problems, samsung, tegra,
>>> etc.. They solved it with driver specific PM notifiers where they used to
>>> disable their driver's ->target() routine.
>>> - Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found an issue where tunables
>>> configuration for clusters/sockets with non-boot CPUs was getting lost after
>>> suspend/resume, as we were notifying governors with CPUFREQ_GOV_POLICY_EXIT on
>>> removal of the last cpu for that policy and so deallocating memory for
>>> tunables. This is fixed by this patch as we don't allow any operation on
>>> governors after device suspend and before device resume now.
>>
>> The series,
>> Tested-by: Stephen Warren <swarren@nvidia.com>
>
> Is this series necessary to fix bugs that you're seeing in 3.14-rc and if so,
> the what bugs are they?

No, Viresh sent a separate patch that fixed the sysfs warning I was
getting (I believe you've already applied that), and there's still some
ongoing discussion about the other kernel spew.