linux-kernel - [PATCH] cpufreq/amd-pstate: Fix min_limit perf and freq updation for performance governor

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Message-ID: <20250407081925.850473-1-dhananjay.ugwekar@amd.com>
Date: Mon, 7 Apr 2025 08:19:26 +0000
From: Dhananjay Ugwekar <dhananjay.ugwekar@....com>
To: <gautham.shenoy@....com>, <mario.limonciello@....com>
CC: <linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>, "Dhananjay
 Ugwekar" <dhananjay.ugwekar@....com>
Subject: [PATCH] cpufreq/amd-pstate: Fix min_limit perf and freq updation for performance governor

The min_limit perf and freq values can get disconnected with performance
governor, as we only modify the perf value in the special case. Fix that
by modifying the perf and freq values together

Fixes: 009d1c29a451 ("cpufreq/amd-pstate: Move perf values into a union")
Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@....com>
---
 drivers/cpufreq/amd-pstate.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 024d33d5e367..76aa4a3698c3 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -607,13 +607,16 @@ static void amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 	union perf_cached perf = READ_ONCE(cpudata->perf);
 
 	perf.max_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->max);
-	perf.min_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->min);
+	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
 
-	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
+	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) {
 		perf.min_limit_perf = min(perf.nominal_perf, perf.max_limit_perf);
+		WRITE_ONCE(cpudata->min_limit_freq, min(cpudata->nominal_freq, cpudata->max_limit_freq));
+	} else {
+		perf.min_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->min);
+		WRITE_ONCE(cpudata->min_limit_freq, policy->min);
+	}
 
-	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
-	WRITE_ONCE(cpudata->min_limit_freq, policy->min);
 	WRITE_ONCE(cpudata->perf, perf);
 }
 
-- 
2.34.1