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cpufreq: intel_pstate: Fix active mode offline/online EPP handling

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After commit 4adcf2e5829f ("cpufreq: intel_pstate: Add ->offline and
->online callbacks") the EPP value set by the "performance" scaling
algorithm in the active mode is not restored after an offline/online
cycle which replaces it with the saved EPP value coming from user
space.

Address this issue by forcing intel_pstate_hwp_set() to set a new
EPP value when it runs first time after online.

Fixes: 4adcf2e5829f ("cpufreq: intel_pstate: Add ->offline and ->online callbacks")
Link: https://lore.kernel.org/linux-pm/adc7132c8655bd4d1c8b6129578e931a14fe1db2.camel@linux.intel.com/
Reported-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2021-11-17 14:57:31 +01:00
parent cd23f02f16
commit ed38eb49d1
1 changed files with 6 additions and 0 deletions
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6
drivers/cpufreq/intel_pstate.c
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@ -1006,6 +1006,12 @@ static void intel_pstate_hwp_offline(struct cpudata *cpu)
*/
value &= ~GENMASK_ULL(31, 24);
value |= HWP_ENERGY_PERF_PREFERENCE(cpu->epp_cached);
/*
* However, make sure that EPP will be set to "performance" when
* the CPU is brought back online again and the "performance"
* scaling algorithm is still in effect.
*/
cpu->epp_policy = CPUFREQ_POLICY_UNKNOWN;
}
/*