Hi Ross, A few things on top of what Guenter already said: On Sun, 17 Mar 2013 14:05:05 +0800, Ross Moore wrote: > Here is the output of pwmconfig - I was noting the pwm and fan are on the > same chip; perhaps they always are. Not always, but most of the time, yes. This is the easiest way to implement automatic (hardware-controlled) fan speed control. > But note the correlation plots in here. > It seems pwm is controlling the fans in any kind of consistent manner > (although clearly there is a link): > > # pwmconfig revision 5857 (2010-08-22) > This program will search your sensors for pulse width modulation (pwm) > controls, and test each one to see if it controls a fan on > your motherboard. Note that many motherboards do not have pwm > circuitry installed, even if your sensor chip supports pwm. > > We will attempt to briefly stop each fan using the pwm controls. > The program will attempt to restore each fan to full speed > after testing. However, it is ** very important ** that you > physically verify that the fans have been to full speed > after the program has completed. > > Found the following devices: > hwmon0 is acpitz > hwmon1/device is coretemp > hwmon2/device is it8771 > hwmon3 is asus You have 3 different drivers presumably accessing the same chip: thermal (ACPI), it87 (native) and asus-wmi (WMI.) This is not a good idea. I suppose you had to boot with acpi_enforce_resources=lax to be able to load the it87 driver? Can we see the output of "sensors" on your machine? Which kernel version are you running? What board is this? Do you have any fan speed control related option in the BIOS, and if so, what did you set it to? Are you using 3-pin fans, 4-pin fans or a mix of both? > > Found the following PWM controls: > hwmon2/device/pwm1 > hwmon2/device/pwm2 > hwmon2/device/pwm3 > > Giving the fans some time to reach full speed... > Found the following fan sensors: > hwmon2/device/fan1_input current speed: 2227 RPM > hwmon2/device/fan2_input current speed: 1211 RPM > > Warning!!! This program will stop your fans, one at a time, > for approximately 5 seconds each!!! > This may cause your processor temperature to rise!!! > If you do not want to do this hit control-C now!!! > Hit return to continue: > > Testing pwm control hwmon2/device/pwm1 ... > hwmon2/device/fan1_input ... speed was 2227 now 1115 > It appears that fan hwmon2/device/fan1_input > is controlled by pwm hwmon2/device/pwm1 > Would you like to generate a detailed correlation (y)? y > Note: If you had gnuplot installed, I could generate a graphical plot. > PWM 255 FAN 1256 > PWM 240 FAN 1149 > PWM 225 FAN 1256 > PWM 210 FAN 1388 > PWM 195 FAN 1599 > PWM 180 FAN 1795 > PWM 165 FAN 1739 > PWM 150 FAN 1683 > PWM 135 FAN 1562 > PWM 120 FAN 1490 > PWM 105 FAN 1400 > PWM 90 FAN 1313 > PWM 75 FAN 1250 > PWM 60 FAN 1194 > PWM 45 FAN 1121 > PWM 30 FAN 1112 > PWM 28 FAN 1113 > PWM 26 FAN 1112 > PWM 24 FAN 1112 > PWM 22 FAN 1113 > PWM 20 FAN 1112 > PWM 18 FAN 1112 > PWM 16 FAN 1113 > PWM 14 FAN 1112 > PWM 12 FAN 1113 > PWM 10 FAN 1112 > PWM 8 FAN 1113 > PWM 6 FAN 1112 > PWM 4 FAN 1112 > PWM 2 FAN 1112 > PWM 0 FAN 1112 The response curve is very odd. Not only fan speed is increasing from PWM 255 to PWM 180, but the maximum speed never reaches the original speed. This makes me wonder what the original PWM value was. I'll prepare a modified version of pwmconfig which prints this information. > > hwmon2/device/fan2_input ... speed was 1211 now 1207 > no correlation > > Testing pwm control hwmon2/device/pwm2 ... > hwmon2/device/fan1_input ... speed was 2227 now 2419 > no correlation > hwmon2/device/fan2_input ... speed was 1211 now 0 > It appears that fan hwmon2/device/fan2_input > is controlled by pwm hwmon2/device/pwm2 > Would you like to generate a detailed correlation (y)? y > Note: If you had gnuplot installed, I could generate a graphical plot. > PWM 255 FAN 548 > PWM 240 FAN 258 > PWM 225 FAN 360 (probably incorrect) > PWM 210 FAN 547 (probably incorrect) > PWM 195 FAN 734 (probably incorrect) > PWM 180 FAN 891 (probably incorrect) > PWM 165 FAN 903 (probably incorrect) > PWM 150 FAN 853 (probably incorrect) > PWM 135 FAN 791 (probably incorrect) > PWM 120 FAN 724 (probably incorrect) > PWM 105 FAN 651 (probably incorrect) > PWM 90 FAN 573 (probably incorrect) > PWM 75 FAN 485 (probably incorrect) > PWM 60 FAN 382 (probably incorrect) > PWM 45 FAN 188 > PWM 30 FAN 0 > Fan Stopped at PWM = 30 This is pretty chaotic. Note that we don't have a datasheet for the IT8771E, support is still considered experimental. So it may well be that we got the fan speed control code wrong. I would like you to check if PWM values stick. Please go to /sys/class/hwmon/hwmon2/device, check the values of files pwm1 and pwm2, see if they change on their own. Then try writing arbitrary values to them, and check if the value is sticking for one minute. I have made a test version of pwmconfig available at: http://khali.linux-fr.org/devel/misc/pwmconfig Please give it a try. The correlations will take much longer because I have set the step to 1, but hopefully it will teach us something. -- Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
