On 11/15/2013 06:22 PM, Viresh Kumar wrote:
On 15 November 2013 13:45, Lan Tianyu <tianyu....@intel.com> wrote:
Currently, governor of nonboot cpus will be put to EXIT when system suspend.
Since all these cpus will be unplugged and the governor usage_count decreases
to zero. The governor data and its sysfs interfaces will be freed or released.
This makes user config of these governors loss during suspend and resume.
This doesn't happen on the governor covering boot cpu because it isn't
unplugged during system suspend.
To fix this issue, skipping governor exit during system suspend and check
policy governor data to determine whether the governor is really needed
to be initialized when do init. If not, return EALREADY to indicate the
governor has been initialized and should do nothing. __cpufreq_governor()
convert EALREADY to 0 as return value for INIT event since governor is
still under INIT state and can do START operation.
Signed-off-by: Lan Tianyu <tianyu....@intel.com>
---
Hi Lan..
Hi Viresh:
Apologies!!
I already had a solution for this as this was reported by few Broadcom people
as well. But I haven't send it to mainline yet as it was untested. It
looked similar
to what you had..
And so I would have taken your patch (as you have sent it first to the list and
there is no real advantage of my patch over yours, they were almost same) :)
But then I went chasing another bug posted by Nishant:
https://lkml.org/lkml/2013/10/24/369
And the final solution I have to write solved all the problems you and he
reported.
Please have a look at that patch (you are cc'd) and give it a try to see
if it fixes your problem..
Never mind. I think it should work and will try it.
Btw, One question about your setup:
- you must have a multi cluster/socket SoC as you have atleast one more
policy structure than used for group containing boot cpu..
Actually, I test on a laptop and find this issue when reading code to
fix other bug. :)
All cpus have their own policys.
- Are you using separate governor for both groups?
Just to produce the bug, I set one non-boot cpu to conservative gov. All
other remain default "ondemand".
- Or are you using CPUFREQ_HAVE_GOVERNOR_PER_POLICY stuff
to use same governor with separate tunables for both groups?
No, I am not using this.
Just wanted to know if somebody else is also using
CPUFREQ_HAVE_GOVERNOR_PER_POLICY :)
--
Best Regards
Tianyu Lan
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