linux-kernel - [PATCH 1/2] cpufreq: CPPC: Don't warn on failing to read perf counters on offline cpus

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Message-ID: <20250730032312.167062-2-yubowen8@huawei.com>
Date: Wed, 30 Jul 2025 11:23:11 +0800
From: Bowen Yu <yubowen8@...wei.com>
To: <rafael@...nel.org>, <viresh.kumar@...aro.org>
CC: <linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linuxarm@...wei.com>, <jonathan.cameron@...wei.com>,
	<zhanjie9@...ilicon.com>, <lihuisong@...wei.com>, <zhenglifeng1@...wei.com>,
	<yubowen8@...wei.com>
Subject: [PATCH 1/2] cpufreq: CPPC: Don't warn on failing to read perf counters on offline cpus

From: Jie Zhan <zhanjie9@...ilicon.com>

Reading perf counters on offline cpus should be expected to fail, e.g. it
returns -EFAULT as counters are shown to be 0. Remove the unnecessary
warning print on this failure path.

Signed-off-by: Jie Zhan <zhanjie9@...ilicon.com>
Signed-off-by: Bowen Yu <yubowen8@...wei.com> # Changing loglevel to debug
---
 drivers/cpufreq/cppc_cpufreq.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index a1fd0ff22bc5..904006027df2 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -144,16 +144,14 @@ static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
 		init_irq_work(&cppc_fi->irq_work, cppc_irq_work);
 
 		ret = cppc_get_perf_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
-		if (ret) {
-			pr_warn("%s: failed to read perf counters for cpu:%d: %d\n",
-				__func__, cpu, ret);
-
+		if (ret && cpu_online(cpu)) {
 			/*
 			 * Don't abort if the CPU was offline while the driver
 			 * was getting registered.
 			 */
-			if (cpu_online(cpu))
-				return;
+			pr_debug("%s: failed to read perf counters for cpu:%d: %d\n",
+				__func__, cpu, ret);
+			return;
 		}
 	}
 
-- 
2.33.0