linux-kernel - [PATCH v7 4/4] cpufreq: qcom-hw: Fix the frequency returned by cpufreq

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Date:   Thu, 17 Nov 2022 11:01:45 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To:     andersson@...nel.org, viresh.kumar@...aro.org,
        krzysztof.kozlowski+dt@...aro.org, rafael@...nel.org,
        robh+dt@...nel.org
Cc:     johan@...nel.org, devicetree@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
        stable@...r.kernel.org, Sudeep Holla <sudeep.holla@....com>
Subject: [PATCH v7 4/4] cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()

The cpufreq_driver->get() callback is supposed to return the current
frequency of the CPU and not the one requested by the CPUFreq core.
Fix it by returning the frequency that gets supplied to the CPU after
the DCVS operation of EPSS/OSM.

Cc: stable@...r.kernel.org # v5.15
Fixes: 2849dd8bc72b ("cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver")
Reported-by: Sudeep Holla <sudeep.holla@....com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 42 +++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 1faa325d3e52..62f36c76e26c 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -131,7 +131,35 @@ static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
 	return 0;
 }
 
+static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
+{
+	unsigned int lval;
+
+	if (qcom_cpufreq.soc_data->reg_current_vote)
+		lval = readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_current_vote) & 0x3ff;
+	else
+		lval = readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_domain_state) & 0xff;
+
+	return lval * xo_rate;
+}
+
+/* Get the current frequency of the CPU (after throttling) */
 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
+{
+	struct qcom_cpufreq_data *data;
+	struct cpufreq_policy *policy;
+
+	policy = cpufreq_cpu_get_raw(cpu);
+	if (!policy)
+		return 0;
+
+	data = policy->driver_data;
+
+	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
+}
+
+/* Get the frequency requested by the cpufreq core for the CPU */
+static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
 {
 	struct qcom_cpufreq_data *data;
 	const struct qcom_cpufreq_soc_data *soc_data;
@@ -292,18 +320,6 @@ static void qcom_get_related_cpus(int index, struct cpumask *m)
 	}
 }
 
-static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
-{
-	unsigned int lval;
-
-	if (qcom_cpufreq.soc_data->reg_current_vote)
-		lval = readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_current_vote) & 0x3ff;
-	else
-		lval = readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_domain_state) & 0xff;
-
-	return lval * xo_rate;
-}
-
 static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
 {
 	struct cpufreq_policy *policy = data->policy;
@@ -347,7 +363,7 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
 	 * If h/w throttled frequency is higher than what cpufreq has requested
 	 * for, then stop polling and switch back to interrupt mechanism.
 	 */
-	if (throttled_freq >= qcom_cpufreq_hw_get(cpu))
+	if (throttled_freq >= qcom_cpufreq_get_freq(cpu))
 		enable_irq(data->throttle_irq);
 	else
 		mod_delayed_work(system_highpri_wq, &data->throttle_work,
-- 
2.25.1