• Shawn Guo's avatar
    cpufreq: qcom-hw: drop devm_xxx() calls from init/exit hooks · 67fc209b
    Shawn Guo authored
    Commit f17b3e44 ("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: f17b3e44 ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code")
    Suggested-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
    Signed-off-by: default avatarShawn Guo <shawn.guo@linaro.org>
    Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
    67fc209b
qcom-cpufreq-hw.c 11.9 KB