Messages in this thread | | | Date | Thu, 2 Jul 2020 12:41:52 +0100 | From | Ionela Voinescu <> | Subject | Re: [PATCH 4/8] cpufreq,vexpress-spc: fix Frequency Invariance (FI) for bL switching |
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Hi,
On Thursday 02 Jul 2020 at 08:35:51 (+0530), Viresh Kumar wrote: > On 01-07-20, 15:07, Ionela Voinescu wrote: > > On Wednesday 01 Jul 2020 at 16:16:19 (+0530), Viresh Kumar wrote: > > > Is there anyone who cares for this driver and EAS ? I will just skip doing the > > > FIE thing here and mark it skipped. > > > > That is a good question. The vexpress driver is still used for TC2, but > > I don't know of any users of this bL switcher functionality that's part > > of the driver. I think there were a few people wondering recently if > > it's still used [1]. > > Even if it is used by some, there is no need, I believe, to enable > freq-invariance for it, which wasn't enabled until now. >
It was enabled until now, but it was partially broken. If you look over the driver you'll see arch_set_freq_scale() being called for both is_bL_switching_enabled() and for when it's not [1].
For !is_bL_switching_enabled() this is fine. But for is_bL_switching_enabled(), it is broken as described in 4/8.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/cpufreq/vexpress-spc-cpufreq.c?h=v5.8-rc3#n203
> And considering that we are going to enable the flag only for the > interested parties now, as from the discussion on 1/8, this shouldn't > be required. >
If we just don't want frequency invariance for is_bL_switching_enabled(), I can just guard the setting of the flag suggested by Rafael at 1/8 by !CONFIG_BL_SWITCHER.
I'll proceed to do that and remove the fix at 4/8.
Many thanks! Ionela.
> -- > viresh
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