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Wysocki" , Viresh Kumar Cc: Prashant Malani , Beata Michalska , "Rafael J. Wysocki" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" AMU counters on certain CPPC-based platforms tend to yield inaccurate delivered performance measurements on systems that are idle/mostly idle. This results in an inaccurate frequency being stored by cpufreq in its policy structure when the CPU is brought online. [1] Consequently, if the userspace governor tries to set the frequency to a new value, there is a possibility that it would be the erroneous value stored earlier. In such a scenario, cpufreq would assume that the requested frequency has already been set and return early, resulting in the correct/new frequency request never making it to the hardware. Since the operating frequency is liable to this sort of inconsistency, mark the CPPC driver with CPUFREQ_NEED_UPDATE_LIMITS so that it is always invoked when a target frequency update is requested. [1] https://lore.kernel.org/linux-pm/20250619000925.415528-3-pmalani@google= .com/ Cc: Beata Michalska Cc: Viresh Kumar Suggested-by: Rafael J. Wysocki Signed-off-by: Prashant Malani Acked-by: Viresh Kumar --- drivers/cpufreq/cppc_cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index a1fd0ff22bc5..4a17162a392d 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -910,7 +910,7 @@ static struct freq_attr *cppc_cpufreq_attr[] =3D { }; =20 static struct cpufreq_driver cppc_cpufreq_driver =3D { - .flags =3D CPUFREQ_CONST_LOOPS, + .flags =3D CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .verify =3D cppc_verify_policy, .target =3D cppc_cpufreq_set_target, .get =3D cppc_cpufreq_get_rate, --=20 2.50.0.727.gbf7dc18ff4-goog