Hi Simon, On Tue, 16 Jul 2013 19:04:39 +0200, Simon Sandström wrote: > I'm having trouble with the asus_atk0110 kernel module. The speed for fan3 > (CHASSI2 FAN) often just shows zero, but once in awhile it shows the actual > speed of the fan. I've checked the fan, and it does spin at all time and it > also shows the correct speed at all time in BIOS. Which motherboard is it? On some boards passing module parameter new_if=1 helps, you may want to give it a try. Also, the asus_atk0110 driver heavily relies on the BIOS, so a BIOS update may help. Note that the fact that the speed in the BIOS is right doesn't necessarily mean that the BIOS is right and the asus_atk0110 Linux kernel driver is wrong. If the fan has any form of automatic speed control applied, it might simply be that the BIOS keeps your machine busy enough for the fan to stay in the measurable speed area. Did you enable fan speed control in the BIOS? Does the problem go away if you (temporarily) disable it? For 3-pin fans, speed measurement is easy and reliable when the fan runs at full speed. However as soon as control is applied, measurement becomes harder. This is true when PWM control is used, but even more when DC control is used: the speed signal weakens as the voltage is lowered, and after some point it's difficult for the monitoring chip to distinguish between the speed signal and the noise. So maybe your fan is spinning at the border between readable and unreadable. > There is also a slight delay when reading the input with "cat > /sys/class/hwmon/hwmon0/fan3_input". When the speed is zero, it takes > approx. 0.3s and when it shows the correct speed (700RPM) it takes 0.1s. > All other fan inputs respond with no delay (0.001s). Not necessarily surprising. I don't know how exactly the Asus BIOS code works, but I can imagine that they try harder when the fan speed they read at first looks suspicious. This would explain the extra delay. > (...) > Does anyone else have this problem, or any similar problem? I could just > connect the fan to fan4 and ignore fan3, but for some reason the minimum > speed for fan4 is 800RPM (the others are 600RPM), and I like my fans > running at 700RPM.. How do you keep them at exactly 700 RPM? -- Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
