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From: zuoqian <zuoqian113@gmail.com>
To: sudeep.holla@arm.com, rafael@kernel.org, viresh.kumar@linaro.org
Cc: cristian.marussi@arm.com, arm-scmi@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org, zuoqian <zuoqian113@gmail.com>
Subject: [PATCH] cpufreq: scpi: compare against frequency instead of rate
Date: Thu, 23 Jan 2025 07:53:20 +0000	[thread overview]
Message-ID: <20250123075321.4442-1-zuoqian113@gmail.com> (raw)

The CPU rate from clk_get_rate() may not be divisible by 1000
(e.g., 133333333). But the rate calculated from frequency is always
divisible by 1000 (e.g., 133333000).
Comparing the rate causes a warning during CPU scaling:
"cpufreq: __target_index: Failed to change cpu frequency: -5".
When we choose to compare frequency here, the issue does not occur.

Signed-off-by: zuoqian <zuoqian113@gmail.com>
---
 drivers/cpufreq/scpi-cpufreq.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index cd89c1b9832c..3bff4bb5ab4a 100644
--- a/drivers/cpufreq/scpi-cpufreq.c
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -39,8 +39,9 @@ static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
 static int
 scpi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
 {
-	u64 rate = policy->freq_table[index].frequency * 1000;
+	unsigned long freq = policy->freq_table[index].frequency;
 	struct scpi_data *priv = policy->driver_data;
+	u64 rate = freq * 1000;
 	int ret;
 
 	ret = clk_set_rate(priv->clk, rate);
@@ -48,7 +49,7 @@ scpi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
 	if (ret)
 		return ret;
 
-	if (clk_get_rate(priv->clk) != rate)
+	if (clk_get_rate(priv->clk) / 1000 != freq)
 		return -EIO;
 
 	return 0;
-- 
2.43.0


             reply	other threads:[~2025-01-23  7:55 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-23  7:53 zuoqian [this message]
2025-01-23 11:12 ` [PATCH] cpufreq: scpi: compare against frequency instead of rate Dan Carpenter
2025-01-23 12:16   ` Sudeep Holla
2025-01-23 13:04     ` Dan Carpenter
2025-01-24  9:42       ` zuoqian
2025-01-24 10:51         ` Dan Carpenter
2025-01-25  8:49 ` [PATCH v2] cpufreq: scpi: compare kHz instead of Hz zuoqian
2025-01-25 13:04   ` Dan Carpenter
2025-02-03 10:51     ` Viresh Kumar
2025-03-06 11:01   ` Dan Carpenter

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