[PATCH AUTOSEL 5.6 049/129] thermal/drivers/cpufreq_cooling: Fix return of cpufreq_set_cur_state

Sasha Levin
2020-04-15T13:10:28Z

From: Willy Wolff <willy.mh.wolff.ml@gmail.com>

[ Upstream commit ff44f672d74178b3be19d41a169b98b3e391d4ce ]

When setting the cooling device current state from userspace via sysfs,
the operation fails by returning an -EINVAL.

It appears the recent changes with the per-policy frequency QoS
introduced a regression as reported by:

https://lkml.org/lkml/2020/3/20/599

The function freq_qos_update_request returns 0 or 1 describing update
effectiveness, and a negative error code on failure. However,
cpufreq_set_cur_state returns 0 on success or an error code otherwise.

Consider the QoS update as successful if the function does not return
an error.

Fixes: 3000ce3c52f8b ("cpufreq: Use per-policy frequency QoS")
Signed-off-by: Willy Wolff <willy.mh.wolff.ml@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200321092740.7vvwfxsebcrznydh@macmini.local
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/thermal/cpufreq_cooling.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
index fe83d7a210d47..af55ac08e1bd5 100644
--- a/drivers/thermal/cpufreq_cooling.c
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -431,6 +431,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
{
struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+ int ret;

/* Request state should be less than max_level */
if (WARN_ON(state > cpufreq_cdev->max_level))
@@ -442,8 +443,9 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,

cpufreq_cdev->cpufreq_state = state;

- return freq_qos_update_request(&cpufreq_cdev->qos_req,
- get_state_freq(cpufreq_cdev, state));
+ ret = freq_qos_update_request(&cpufreq_cdev->qos_req,
+ get_state_freq(cpufreq_cdev, state));
+ return ret < 0 ? ret : 0;
}

/* Bind cpufreq callbacks to thermal cooling device ops */
--
2.20.1