On 09/19/2012 05:49 AM, Jean Delvare wrote: > 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. > Yes, my hardware (Vostro 3400) will adjust my fan speed on it's own, but the i8kmon daemon just sets it back in its next polling period. Is this a deal-breaker for lm_sensors? The tcl-based i8kmon daemon uses way more resources than I think is reasonable, it's typically in the top 2 or 3 processes on my machine for CPU time; the mem usage also seems a little high. I started writing something more efficient for my own use and noticed it was quite a bit more efficient to read /proc/i8k and parse the temperature, for example, than issue an ioctl. Let alone ioctls for all of the values. I wonder if adding entries for each setting under /sys/modules/i8k would be accepted. Your mapping make sense to me. Except I'm not sure why you have 128 as I8K_FAN_LOW in the getter and 192 in the setter. (Also, write perms for user(/group) would be nice for the attribute). _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
