2022-11-17 05:47:44

by Manivannan Sadhasivam

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: [email protected] # v5.15
Fixes: 2849dd8bc72b ("cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver")
Reported-by: Sudeep Holla <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
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

2022-11-21 05:12:27

by Viresh Kumar

Subject: Re: [PATCH v7 4/4] cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()

On 17-11-22, 11:01, Manivannan Sadhasivam wrote:
> 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: [email protected] # v5.15
> Fixes: 2849dd8bc72b ("cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver")
> Reported-by: Sudeep Holla <[email protected]>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---
> drivers/cpufreq/qcom-cpufreq-hw.c | 42 +++++++++++++++++++++----------
> 1 file changed, 29 insertions(+), 13 deletions(-)

A fix should always be the first patch in the series as it needs to be
backported.

I can reorder this if it won't break anything for this time.

--
viresh