Re: [RFT][PATCH 0/3] cpufreq / PM: QoS: Introduce frequency QoS and use it in cpufreq

[Sudeep Holla]

On Thu, Oct 17, 2019 at 03:27:25PM +0530, Viresh Kumar wrote:
> On 16-10-19, 15:23, Sudeep Holla wrote:
> > Thanks for the spinning these patches so quickly.
> >
> > I did give it a spin, but unfortunately it doesn't fix the bug I reported.
> > So I looked at my bug report in detail and looks like the cpufreq_driver
> > variable is set to NULL at that point and it fails to dereference it
> > while trying to execute:
> > 	ret = cpufreq_driver->verify(new_policy);
> > (Hint verify is at offset 0x1c/28)
> >
> > So I suspect some race as this platform with bL switcher tries to
> > unregister and re-register the cpufreq driver during the boot.
> >
> > I need to spend more time on this as reverting the initial PM QoS patch
> > to cpufreq.c makes the issue disappear.
>
> Is this easily reproducible ? cpufreq_driver == NULL shouldn't be the case, it
> get updated only once while registering/unregistering cpufreq drivers. That is
> the last thing which can go wrong from my point of view :)
>

Yes, if I boot my TC2 with bL switcher enabled, it always crashes on boot.

--
Regards,
Sudeep