On Mon, 02 June 2008 Jean Delvare <khali at linux-fr.org> wrote: > On Mon, 2 Jun 2008 21:09:41 +0200, Bruno Pr?mont wrote: > > On Mon, 02 June 2008 Jean Delvare <khali at linux-fr.org> wrote: > > > Is the fan's speed controlled in any way, either by the W83697HG > > > chip, or maybe it is a self-regulated fan? Just check if the > > > fan's speed increases with the temperature (i.e. with CPU load). > > > > Yes, the fan has a built-in thermal sensor and regulates it's speed > > based on temperature. > > It's running either at its lowest speed or the speed just above. > > Note that I've never seen this behavior on self-regulated fans... But > I guess it depends on the implementation. > > > > (...) > > > One patch you may want to apply it this one: > > > http://lists.lm-sensors.org/pipermail/lm-sensors/2008-May/023189.html > > > It will let you switch the W83697HG chip from automatic fan speed > > > control to manual control and back - might be useful to > > > investigate the issue you have. > > > > I will try this one, maybe the board is capable of doing speed > > control but its not implemented in vanilla driver. > > It is. The w83627hf driver can do manual fan speed control for a very > long time. What it is missing is support for automatic fan speed > control. > > > Until now setting pwm_enable to any values and changing PWM value > > did not influence fan speed > > If setting pwmN_enable to 1 and pwmN to 0 doesn't stop the fan, this > suggests that your motherboard can't do fan speed control. The easiest > way to test is by running the "pwmconfig" script. But anyway, you > would only have been able to slow down the fan, not speed it up, so it > wouldn't have solved the problem. That's what I did, with a standard non-regulated fan and it did not change behavior with pwmN_enable set to 1 and pwmN set to 0 or any other value So the motherboard probably does not support speed control (reason for using self-controlled fan though on/off would still be nice). > > > (...) > > > Filter out very large fan speed values. These can be reported by > > > the chip when a fan is being controlled at low speed. The > > > tachometer signal gets too weak and the chip fails to monitor the > > > speed properly, but unfortunately it reports unreasonably high > > > values instead of 0 RPM, which is quite confusing. > > > > I would prefer it to return the last valid speed if that speed is > > not older than a few seconds though 0 is still better than "out of > > range". > > We just can't do that, it would be lying to the user. We can't tell > the user that his/her fan is spinning at a given speed when it might > actually be spinning way slower or even be plain stalled. Returning 0 is not much better. The best would be to return an error which client application could act on... > > (...) > > I will also check fan behavior on IT8712F which is capable of doing > > PWM control on 3 pin fans (maybe also automatic control, to be > > checked) > > The IT8712F can control the fans in both manual and automatic modes, > but the it87 driver only supports the former. Keep in mind though > that, just because the chip can do it, a motherboard with this chip > may not support fan speed control; it all depends on how the > motherboard is wired. My mainboard (IEI KINO-690S1) with IT8712F can do the speed control, manual control is running properly (just that the range of values which cause fan speed variations is not very intuitive: 0-2-4-6-8 from off to full-speed for all the fans I tried, some also spin only for values of at least 4) The IT reports CPU temperature which is too low (offset? as curves look very similar) - it's below room temperature (e.g. 20-24?C), AMD Turion X2 sensor reports a temperature which makes more sense (e.g. 38-42?C)
