| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 054/179] cpufreq: intel_pstate: Fix active mode offline/online EPP handling | Date | Mon, 29 Nov 2021 19:17:28 +0100 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
commit ed38eb49d101e829ae0f8c0a0d3bf5cb6bcbc6b2 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/cpufreq/intel_pstate.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -999,6 +999,12 @@ static void intel_pstate_hwp_offline(str */ 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; } /*
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