This is a note to let you know that I've just added the patch titled
cpufreq: intel_pstate: Fix energy_performance_preference for passive
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cpufreq-intel_pstate-fix-energy_performance_preferen.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 94d2e5c20f7417c01fcda808dc8cf8cdbc204e4d
Author: Tero Kristo <tero.kristo@xxxxxxxxxxxxxxx>
Date: Wed Jun 21 09:58:39 2023 +0300
cpufreq: intel_pstate: Fix energy_performance_preference for passive
[ Upstream commit 03f44ffb3d5be2fceda375d92c70ab6de4df7081 ]
If the intel_pstate driver is set to passive mode, then writing the
same value to the energy_performance_preference sysfs twice will fail.
This is caused by the wrong return value used (index of the matched
energy_perf_string), instead of the length of the passed in parameter.
Fix by forcing the internal return value to zero when the same
preference is passed in by user. This same issue is not present when
active mode is used for the driver.
Fixes: f6ebbcf08f37 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled")
Reported-by: Niklas Neronin <niklas.neronin@xxxxxxxxx>
Signed-off-by: Tero Kristo <tero.kristo@xxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index eee74a2fe3174..2f5063db2f1fc 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -824,6 +824,8 @@ static ssize_t store_energy_performance_preference(
err = cpufreq_start_governor(policy);
if (!ret)
ret = err;
+ } else {
+ ret = 0;
}
}
