On Sat, Apr 11, 2015 at 5:52 AM, Martin Peres <martin.peres at free.fr> wrote: > On 05/02/2015 11:49, Christian König wrote: >> >> Am 04.02.2015 um 23:27 schrieb Alex Deucher: >>> >>> 0-255 seems to be the preferred range for the pwm interface. >>> >>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com> >> >> Yeah, using 100 on a 8bit pwm timer sounds rather obviously wrong. >> >> Patch is Reviewed-by: Christian König <christian.koenig at amd.com> >> >>> --- >>> drivers/gpu/drm/radeon/radeon_pm.c | 8 ++++++-- >>> 1 file changed, 6 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/radeon/radeon_pm.c >>> b/drivers/gpu/drm/radeon/radeon_pm.c >>> index 91e1bd2..9f758d3 100644 >>> --- a/drivers/gpu/drm/radeon/radeon_pm.c >>> +++ b/drivers/gpu/drm/radeon/radeon_pm.c >>> @@ -585,7 +585,7 @@ static ssize_t radeon_hwmon_set_pwm1_enable(struct >>> device *dev, >>> if (err) >>> return err; >>> - switch(value) { >>> + switch (value) { >>> case 1: /* manual, percent-based */ >>> rdev->asic->dpm.fan_ctrl_set_mode(rdev, >>> FDO_PWM_MODE_STATIC); >>> break; >>> @@ -608,7 +608,7 @@ static ssize_t radeon_hwmon_get_pwm1_max(struct >>> device *dev, >>> struct device_attribute *attr, >>> char *buf) >>> { >>> - return sprintf(buf, "%i\n", 100); /* pwm uses percent-based >>> fan-control */ >>> + return sprintf(buf, "%i\n", 255); >>> } > > > This is not a standard name as it is not documented in > https://www.kernel.org/doc/Documentation/hwmon/sysfs-interface > > Apparently, the pwm value should always have been exposed as 0-255 and I > screwed it up in nouveau by having it be 0-100... > > Maybe we should ask pwm*_max to be defined so as new applications could do > the right thing while not having nouveau change its ABI. I guess it is ok to > change it for radeon as there are so few users currently but the interface > has been in nouveau for multiple years already! >
IIRC, I changed it in the same kernel as the original patch went in. Alex