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

Rafael J. Wysocki
2014-02-18T23:16:45Z

On Tuesday, February 18, 2014 03:26:01 PM Stephen Warren wrote:
> 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.

OK, thanks!

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.