Re: [PATCH] cpufreq: qcom-hw: add missing devm_release_mem_region() call

[Ionela Voinescu <ionela.voinescu@arm.com>]

Hi guys,

On Tuesday 12 Jan 2021 at 19:19:29 (+0800), Shawn Guo wrote:
> On Tue, Jan 12, 2021 at 03:44:49PM +0530, Viresh Kumar wrote:
> > On 12-01-21, 17:52, Shawn Guo wrote:
> > > On SDM845/850, running the following commands to put all cores in
> > > freq-domain1 offline and then get one core back online, there will be
> > > a request region error seen from qcom-hw driver.
> > > 
> > > $ echo 0 > /sys/devices/system/cpu/cpu4/online
> > > $ echo 0 > /sys/devices/system/cpu/cpu5/online
> > > $ echo 0 > /sys/devices/system/cpu/cpu6/online
> > > $ echo 0 > /sys/devices/system/cpu/cpu7/online
> > > $ echo 1 > /sys/devices/system/cpu/cpu4/online
> > > 
> > > [ 3395.915416] CPU4: shutdown
> > > [ 3395.938185] psci: CPU4 killed (polled 0 ms)
> > > [ 3399.071424] CPU5: shutdown
> > > [ 3399.094316] psci: CPU5 killed (polled 0 ms)
> > > [ 3402.139358] CPU6: shutdown
> > > [ 3402.161705] psci: CPU6 killed (polled 0 ms)
> > > [ 3404.742939] CPU7: shutdown
> > > [ 3404.765592] psci: CPU7 killed (polled 0 ms)
> > > [ 3411.492274] Detected VIPT I-cache on CPU4
> > > [ 3411.492337] GICv3: CPU4: found redistributor 400 region 0:0x0000000017ae0000
> > > [ 3411.492448] CPU4: Booted secondary processor 0x0000000400 [0x516f802d]
> > > [ 3411.503654] qcom-cpufreq-hw 17d43000.cpufreq: can't request region for resource [mem 0x17d45800-0x17d46bff]
> > > 
> > > The cause is that the memory region requested in .init hook doesn't get
> > > released in .exit hook, and the subsequent call to .init will always fail
> > > on this error.  Let's break down the devm_platform_ioremap_resource()
> > > call a bit, so that we can have the resource pointer to release memory
> > > region from .exit hook.
> > > 
> > > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> > > ---
> > >  drivers/cpufreq/qcom-cpufreq-hw.c | 8 +++++++-
> > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > FWIW, Ionela also sent a fix though I like this one better for the
> > obvious reasons.
> > 
> > https://lore.kernel.org/lkml/20210108151406.23595-1-ionela.voinescu@arm.com/
> 
> Ha, thanks for the pointer.  So the original code was tricky and skipped
> the region request call intentionally.
> 

As long as the problem is fixed, I'm happy :).
For this patch:
Tested-by: Ionela Voinescu <ionela.voinescu@arm.com>

The patch probably deserves:
Fixes: f17b3e44320b ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code")

Thanks,
Ionela.

> Shawn