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cpufreq/amd-pstate: Reorder notifier unregistration and floor perf reset

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An active power supply notifier can race with amd_pstate_epp_cpu_exit()
trying to reset the floor perf and can overwrite the floor perf set in
MSR_AMD_CPPC_REQ.

Unregister the notifier before setting the floor perf to prevent the
rare race.

Fixes: e30ca6dd53 ("cpufreq/amd-pstate: Add dynamic energy performance preference")
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260508051748.10484-5-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
This commit is contained in:
K Prateek Nayak 2026-05-08 05:17:46 +00:00 committed by Mario Limonciello (AMD)
parent c5eed6ddc7
commit f3acf7ff11
1 changed files with 3 additions and 2 deletions
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5
drivers/cpufreq/amd-pstate.c
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@ -1982,12 +1982,13 @@ static void amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
if (cpudata) {
union perf_cached perf = READ_ONCE(cpudata->perf);
if (cpudata->dynamic_epp)
amd_pstate_clear_dynamic_epp(policy);
/* Reset CPPC_REQ MSR to the BIOS value */
amd_pstate_update_perf(policy, perf.bios_min_perf, 0U, 0U, 0U, false);
amd_pstate_set_floor_perf(policy, cpudata->bios_floor_perf);
if (cpudata->dynamic_epp)
amd_pstate_clear_dynamic_epp(policy);
kfree(cpudata);
policy->driver_data = NULL;
}