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From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Subject: [PATCH v1] cpufreq: intel_pstate: Set non-turbo capacity to HWP_GUARANTEED_PERF()
Date: Tue, 07 Jul 2026 19:19:55 +0200	[thread overview]
Message-ID: <12928972.O9o76ZdvQC@rafael.j.wysocki> (raw)

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Setting cpu->capacity_perf to cpu->pstate.max_pstate_physical in the
"no turbo" case is inconsistent with what happens elsewhere in the
driver and causes arch_scale_cpu_capacity() to be incorrect.  It also
skews arch_scale_freq_capacity() which ends up differing from 1024 for
the guaranteed P-state.

Address that by setting capacity_perf to HWP_GUARANTEED_PERF() in the
"no turbo" case.

Fixes: 929ebc93ccaa ("cpufreq: intel_pstate: Set asymmetric CPU capacity on hybrid systems")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All applicable <stable@vger.kernel.org>
---
 drivers/cpufreq/intel_pstate.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1007,12 +1007,14 @@ static void hybrid_clear_cpu_capacity(un
 
 static void hybrid_get_capacity_perf(struct cpudata *cpu)
 {
+	u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached);
+
 	if (READ_ONCE(global.no_turbo)) {
-		cpu->capacity_perf = cpu->pstate.max_pstate_physical;
+		cpu->capacity_perf = HWP_GUARANTEED_PERF(hwp_cap);
 		return;
 	}
 
-	cpu->capacity_perf = HWP_HIGHEST_PERF(READ_ONCE(cpu->hwp_cap_cached));
+	cpu->capacity_perf = HWP_HIGHEST_PERF(hwp_cap);
 }
 
 static void hybrid_set_capacity_of_cpus(void)




             reply	other threads:[~2026-07-07 17:19 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-07 17:19 Rafael J. Wysocki [this message]
2026-07-07 20:47 ` [PATCH v1] cpufreq: intel_pstate: Set non-turbo capacity to HWP_GUARANTEED_PERF() Ricardo Neri

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