Commit ed38eb49 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

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

After commit 4adcf2e5 ("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: 4adcf2e5 ("cpufreq: intel_pstate: Add ->offline and ->online callbacks")
Link: https://lore.kernel.org/linux-pm/adc7132c8655bd4d1c8b6129578e931a14fe1db2.camel@linux.intel.com/


Reported-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent cd23f02f

drivers/cpufreq/intel_pstate.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

	}



	/*