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    SubjectRe: [PATCH] cpufreq: longhaul: Set transition_delay_us to 20 ms

    > The commit e948bc8fbee0 ("cpufreq: Cap the default transition delay
    > value to 10 ms") caused a regression on EPIA-M min-ITX computer where
    > shutdown or reboot hangs occasionally with a print message like:
    >
    > longhaul: Warning: Timeout while waiting for idle PCI bus
    > cpufreq: __target_index: Failed to change cpu frequency: -16
    >
    > This probably happens because the cpufreq governor tries to change the
    > frequency of the CPU faster than allowed by the hardware.
    >
    > With the above commit, the default transition delay comes to 10 ms for a
    > transition_latency of 200 us. Set the default transition delay to 20 ms
    > directly to fix this regression.
    >
    > Fixes: e948bc8fbee0 ("cpufreq: Cap the default transition delay value to 10 ms")
    > Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
    > Reported-by: Meelis Roos <mroos@linux.ee>
    > Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net>
    > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
    > ---
    > drivers/cpufreq/longhaul.c | 2 +-
    > 1 file changed, 1 insertion(+), 1 deletion(-)
    >
    > diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
    > index c46a12df40dd..56eafcb07859 100644
    > --- a/drivers/cpufreq/longhaul.c
    > +++ b/drivers/cpufreq/longhaul.c
    > @@ -894,7 +894,7 @@ static int longhaul_cpu_init(struct cpufreq_policy *policy)
    > if ((longhaul_version != TYPE_LONGHAUL_V1) && (scale_voltage != 0))
    > longhaul_setup_voltagescaling();
    >
    > - policy->cpuinfo.transition_latency = 200000; /* nsec */
    > + policy->transition_delay_us = 20000; /* usec */
    >
    > return cpufreq_table_validate_and_show(policy, longhaul_table);
    > }

    This patch also works on my EPIA-M board - tested 10+ times.

    Sorry it took so long to test, it was a remote computer.

    --
    Meelis Roos (mroos@linux.ee)

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