[PATCH 4.20 07/57] cpufreq: scmi: Fix frequency invariance in slow path

From: Greg Kroah-Hartman
Date: Tue Jan 15 2019 - 11:44:53 EST


4.20-stable review patch. If anyone has any objections, please let me know.

------------------

From: Quentin Perret <quentin.perret@xxxxxxx>

commit 0e141d1c65c1dd31c914eb2e11651adcc1a15912 upstream.

The scmi-cpufreq driver calls the arch_set_freq_scale() callback on
frequency changes to provide scale-invariant load-tracking signals to
the scheduler. However, in the slow path, it does so while specifying
the current and max frequencies in different units, hence resulting in a
broken freq_scale factor.

Fix this by passing all frequencies in KHz, as stored in the CPUFreq
frequency table.

Fixes: 99d6bdf33877 (cpufreq: add support for CPU DVFS based on SCMI message protocol)
Signed-off-by: Quentin Perret <quentin.perret@xxxxxxx>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Acked-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Cc: 4.17+ <stable@xxxxxxxxxxxxxxx> # v4.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/cpufreq/scmi-cpufreq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c
@@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_p
int ret;
struct scmi_data *priv = policy->driver_data;
struct scmi_perf_ops *perf_ops = handle->perf_ops;
- u64 freq = policy->freq_table[index].frequency * 1000;
+ u64 freq = policy->freq_table[index].frequency;

- ret = perf_ops->freq_set(handle, priv->domain_id, freq, false);
+ ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false);
if (!ret)
arch_set_freq_scale(policy->related_cpus, freq,
policy->cpuinfo.max_freq);