Ticket 1834 Update
mds4 at verizon.net
Tue Dec 7 20:02:46 CET 2004
I'm quite surprised that changing the PWM clock worked, at least sortof...
(it only slowed the fan down 15% max even after the fix)
But 125 kHz is a bad default (and my math and datasheet show a default of 24 MHz / 256 = 93.75 kHz...
Khali where did you get 125 kHz?)
A typical PWM requirement for a fan is 20 - 50 kHz.
It may be worth enhancing the driver to set the speed lower if the BIOS doesn't.
Jean Delvare wrote:
>>Here the pwmconfig output:
>>Testing pwm control 1-0290/fan1_pwm ...
>> 1-0290/fan1_input ... speed was 2777 now 0
>> It appears that fan 1-0290/fan1_input
>> is controlled by pwm 1-0290/fan1_pwm
>>Would you like to generate a detailed correlation (y)?
>> PWM 255 FAN 3245
>> PWM 240 FAN 3245
>> PWM 225 FAN 3214
>> PWM 210 FAN 3199
>> PWM 195 FAN 3183
>> PWM 180 FAN 3154
>> PWM 165 FAN 3139
>> PWM 150 FAN 3110
>> PWM 135 FAN 3082
>> PWM 120 FAN 3082
>> PWM 105 FAN 3040
>> PWM 90 FAN 3013
>> PWM 75 FAN 2960
>> PWM 60 FAN 2922
>> PWM 45 FAN 2824
>> PWM 30 FAN 2755
>> PWM 15 FAN 0
>> Fan Stopped at PWM = 15
> Wow. Glad it work, I didn't really expected it to. Are you using some
> unconventional fan? You might want to try different clock values, since
> the speed curve is still not perfect.
>>What would be the "nicest" way of setting these values? I would
>>suggest putting it into /etc/modules.conf:
>>post-install w83627hf /usr/sbin/isaset -y 0x295 0x296 0 25 > /dev/null
>> 2> /dev/null
>>Ok? Or is there a better/safer way?
> The driver doesn't need to be loaded for it to work (and actually it
> would probably be better to run isaset before it is) so I would do a
> pre-install. Alternatively you can run the command from any init script,
> it doesn't really matter.
> In cas you need it, the register for PWM 2 is 0x02 and works exactly the
> I'll update and close ticket #1384 now.
>>Thanks a lot. Cheers,
> You're welcome :)
More information about the lm-sensors