The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ed38eb49d101e829ae0f8c0a0d3bf5cb6bcbc6b2 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Date: Wed, 17 Nov 2021 14:57:31 +0100
Subject: [PATCH] cpufreq: intel_pstate: Fix active mode offline/online EPP
handling
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@xxxxxxxxxxxxxxx/
Reported-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Cc: 5.9+ <stable@xxxxxxxxxxxxxxx> # 5.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1088ff350159..1bc00645b656 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -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;
}
/*
