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!
