From: Tero Kristo tero.kristo@linux.intel.com
[ Upstream commit 03f44ffb3d5be2fceda375d92c70ab6de4df7081 ]
If the intel_pstate driver is set to passive mode, then writing the same value to the energy_performance_preference sysfs twice will fail. This is caused by the wrong return value used (index of the matched energy_perf_string), instead of the length of the passed in parameter. Fix by forcing the internal return value to zero when the same preference is passed in by user. This same issue is not present when active mode is used for the driver.
Fixes: f6ebbcf08f37 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled") Reported-by: Niklas Neronin niklas.neronin@intel.com Signed-off-by: Tero Kristo tero.kristo@linux.intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cpufreq/intel_pstate.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index eee74a2fe3174..2f5063db2f1fc 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -824,6 +824,8 @@ static ssize_t store_energy_performance_preference( err = cpufreq_start_governor(policy); if (!ret) ret = err; + } else { + ret = 0; } }