Hi Pavel, On 2005-10-24, Pavel Ruzicka wrote: > It's a little strange. I can't set fan1_min lower than 640. It is expected due to the hardware implementation. The lowest speed that can be monitored (and thus the lowest limit you can set) depends on an internal clock speed and a clock divider. For a divider of 8, this is (32768*60)/(2*8*192) = 640. For lower dividers, the value is even greater. Most chips let you disable the alarm by writing 0 to the limit but these SMSC chips use a different logic and it seems you can't disable the alarm that way. > fan2_div it's possible to change to 1, 2, 4, 8, but minimal limits > are increased. Example of output: > smsc47m1-isa-0800 > Adapter: ISA adapter > fan1: 0 RPM (min = 640 RPM, div = 8) ALARM > fan2: 0 RPM (min = 5120 RPM, div = 1) ALARM See above, this is because the minimum low value is greater with lower dividers. 5120 RPM is the lowest possible value for divider 1. > smsc47m1-isa-0800 > Adapter: ISA adapter > fan1: 0 RPM (min = 640 RPM, div = 8) ALARM > fan2: 1050 RPM (min = 1280 RPM, div = 4) ALARM This is more surprising, as the driver should try to preserve the low limit on divider increment. Unless you actually did it the other way around (4 then 1)? I took a look at the code and it looks correct to me. Anyway, you can set the value again by writing it to fan2_min. > Setting of pwm doesn't work for me, but maybe I can do something wrong. > > sensors -s tells me: > ----------------------- > Error: Line 2047: Unknown feature name > smsc47m1-isa-0800: No such feature known > ----------------------- > > This is part of /etc/sensors.conf: > ------------------- > chip "smsc47m1-*" > set fan2_min 640 > set fan2_div 8 > set pwm1 1 > ------------------- That's expected, as libsensors doesn't know about fan speed control except for a few chips. Typically, PWM operations are done directly through sysfs. Check in /sys/bus/i2c/devices, you should find a directory for your chip and pwm files here. Use with caution, of course. Anyway, the tests above are sufficient to convince me that your chip is compatible with the LPC47M192 as fan as fan control and monitoring is concerned. We will have to update our documentation accordingly. Thanks, -- Jean Delvare
