cpufreq: qcom-hw: drop devm_xxx() calls from init/exit hooks
authorShawn Guo <shawn.guo@linaro.org>
Tue, 19 Jan 2021 02:39:25 +0000 (10:39 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 4 Mar 2021 10:38:41 +0000 (11:38 +0100)
commitb49bee3fb5dc2ce639bfe535768378dbaeaf40bc
tree57dba3f129b39e366ecef56e5b118ce74d38f2aa
parentb3df1eac5a7afd2bea3b44ad9e0089c5d3a22ffb
cpufreq: qcom-hw: drop devm_xxx() calls from init/exit hooks

commit 67fc209b527d023db4d087c68e44e9790aa089ef upstream.

Commit f17b3e44320b ("cpufreq: qcom-hw: Use
devm_platform_ioremap_resource() to simplify code") introduces
a regression on platforms using the driver, by failing to initialise
a policy, when one is created post hotplug.

When all the CPUs of a policy are hoptplugged out, the call to .exit()
and later to devm_iounmap() does not release the memory region that was
requested during devm_platform_ioremap_resource().  Therefore,
a subsequent call to .init() will result in the following error, which
will prevent a new policy to be initialised:

[ 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]

With that being said, the original code was tricky and skipping memory
region request intentionally to hide this issue.  The true cause is that
those devm_xxx() device managed functions shouldn't be used for cpufreq
init/exit hooks, because &pdev->dev is alive across the hooks and will
not trigger auto resource free-up.  Let's drop the use of device managed
functions and manually allocate/free resources, so that the issue can be
fixed properly.

Cc: v5.10+ <stable@vger.kernel.org> # v5.10+
Fixes: f17b3e44320b ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code")
Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/cpufreq/qcom-cpufreq-hw.c