linux-kernel - [PATCH v2] cpufreq: scpi: compare kHz instead of Hz

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Message-ID: <20250125084950.1680-1-zuoqian113@gmail.com>
Date: Sat, 25 Jan 2025 08:49:49 +0000
From: zuoqian <zuoqian113@...il.com>
To: sudeep.holla@....com,
	dan.carpenter@...aro.org,
	cristian.marussi@....com,
	rafael@...nel.org,
	viresh.kumar@...aro.org
Cc: arm-scmi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	zuoqian <zuoqian113@...il.com>
Subject: [PATCH v2] cpufreq: scpi: compare kHz instead of Hz

The CPU rate from clk_get_rate() may not be divisible by 1000
(e.g., 133333333). But the rate calculated from frequency(kHz) 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 kHz here, the issue does not occur.

Fixes: 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
Signed-off-by: zuoqian <zuoqian113@...il.com>
---
V1 -> V2: rename freq to freq_khz, change rate to unsigned long, and
update patch summary.
---
 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..9e09565e41c0 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_khz = policy->freq_table[index].frequency;
 	struct scpi_data *priv = policy->driver_data;
+	unsigned long rate = freq_khz * 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_khz)
 		return -EIO;
 
 	return 0;
-- 
2.43.0