Hi Matthew, On Wed, 19 Sep 2012 00:04:25 -0600, Matthew Monaco wrote: > I am interested in extending the i8k module's hwmon support. This module (among > other things) allows the status of Dell laptop fans to be controlled. The fan > speed is controlled via an integer from 0 (off) to 2 (fast). You can change the desired speed of the fans, not their status. > Is there any way to support these semantics through hwmon? I easily added a > fanN_status sysfs entry through hwmon that does the right thing. However the > _status doesn't follow all other naming conventions that I can find. The standard fan speed control interface is through the pwm* sysfs attributes. However this interface wasn't designed for discrete speed values like the i8k driver offers, so while you can map the 3 discrete values to arbitrary PWM duty cycles (0%, 50% and 100%) it's somewhat confusing. Still, I tried to add support for this over a year ago already: Subject: [PATCH 2/2] Add hwmon-style fan speed control http://marc.info/?l=lm-sensors&m=130270896704113&w=2 But I did not receive any feedback so it didn't go upstream. Note that my limited experience with Dell laptops suggests that at least some models don't behave like the driver claims, changing the fan speed setting in the user's back. That's another reason why the patch didn't go upstream. The problem also exists with the current driver but my patch would make it even more visible, as the pwm* interface is standardized. Feel tree to play with my patch, but I'm not sure we really want to push it upstream. -- Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
