Hi Alex, > > I recall seeing this problem before. The list archives have a similar > > problem for an MSI 975x board: > > http://lists.lm-sensors.org/pipermail/lm-sensors/2007-April/019545.html > > http://lists.lm-sensors.org/pipermail/lm-sensors/2007-April/019566.html > > > > For that board, the solution was that the Intel ICH7 chip controlled > > the fan using a GPIO pin. > > No. This isn't the same problem I have. He uses the 4-pin connector. I > only use two case fans on normal 3-pin connectors which are controllable > by Speedfan under Windows. > > > But he wasn't getting a "Permission denied" > > error. Can you please double-check that you have permission to write > > to the files? I'm not going to quiz you on your setup (SELinux? or a > > problem in /etc/sudoers?) -- but I'll take your word for it that it's > > a driver error and not a sysfs permissions error. > > Good point. I'm so stupid. I do a sudo echo "0" > pwm1. So echo "0" is > executed as root but the file writing not. Ok as root it works. I can > write something into actually pwm4 and the fan stops. > > But pwmconfig does not work either. It says: > > ------------------------------------------------------------ > Found the following PWM controls: > hwmon0/device/pwm1 > hwmon0/device/pwm1_enable stuck to 1 > Failed to set pwmhwmon0/device/pwm1 to full speed > Something's wrong, check your fans! > ------------------------------------------------------------ > > And if I try a echo "0" > pwm1_enable I get "bash: echo: write error: > Invalid argument". echo "2" works. So I think this is one for you. > > > Best Regards and thanks for help > Alex I understand the problem now. In the w83627ehf driver, there is this code: static ssize_t store_pwm_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) ... if (!val || (val > 2)) /* only modes 1 and 2 are supported */ return -EINVAL; That is the "write error: invalid argument" error. The reason this code rejects a write of 0 to pwm_enable is because the w83627ehf does not have a true "disable" mode. Some other chips will set the pwm output to 100% when they are disabled. The w83627ehf doesn't have a disable mode. Of course, setting it to manual and storing 255 in the pwm would do the same thing. That's what pwmconfig (lm_sensors version 2.10.4) does: # Try pwmN_enable=0 echo 0 > $ENABLE 2> /dev/null if [ "`cat $ENABLE`" -eq 0 ] then # Success return 0 fi # It didn't work, try pwmN_enable=1 pwmN=255 echo 1 > $ENABLE 2> /dev/null echo $MAX > $1 if [ "`cat $ENABLE`" -eq 1 -a "`cat $1`" -ge 190 ] then # Success return 0 fi So I *think* the problem is in pwmconfig. But yes, manually writing 0 to pwm_enable will give you an -EINVAL. To be completely honest, I haven't run pwmconfig in a while. I know it generally works, but someone should probably post a patch to get it to work smoothly with w83627ehf and w83627dhg chips. (I could do that... given lots of time :-) Hope that helps, David
