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quintaessentia

Member

From: Florida

Registered: 2010-03-19

Posts: 4

pwmconfig stops fans then errors out

I've done a lot of searching and I haven't been able to find anyone who's had quite the same problem as I'm having. When I run pwmconfig, I get the following:

Found the following devices:
    hwmon0/device is smsc47m1
    hwmon1/device is smsc47m192

Found the following PWM controls:
    hwmon1/device/pwm1
    hwmon1/device/pwm2

Giving the fans some time to reach full speed...

Found the following fan sensors:
    hwmon0/device/fan1_input     current speed: 0 ... skipping!
    hwmon0/device/fan2_input     current speed: 0 ... skipping!

There are no working fan censors, all readings are 0.
make sure you have a 3-wire fan connected.
You may also need to increase the fan divisors.
See doc/fan-divisors for more information.

There is a delay of 5 seconds after the "Giving the fans some time..." and during this delay my fans stop completely, I have to reboot to get them going again. I took a look at the doc/fan-divisors, which suggests putting set fanN_div X into the sensors3.conf file. I tried this and when I ran sensors -s I got the following error:

Error: File /etc/sensors3.conf, line 211: Unknown feature name
smsc47m192-i2c-0-2d: No such subfeature known

I also looked through the pwmconfig bash script file and here's the code for the part that's messing up on me:

278    echo "Giving the fans some time to reach full speed..."
279    sleep $DELAY
280    echo 'Found the following fan sensors:'
281    for i in $FAN
282    do
283            # this will return the first field if there's only one (sysfs)
284            S=`cat $i | cut -d' ' -f2`
285            if [ "$S" = "0" -o "$S" = "-1" ]
286            then
287                    echo "   $i     current speed: 0 ... skipping!"
288            else
289                    echo "   $i     current speed: $S RPM"
290                    if [ "$GOODFAN" = "" ]
291                    then
292                            GOODFAN=$i
293                            SPEEDS=$S
294                    else
295                            GOODFAN="$GOODFAN $i"
296                            SPEEDS="$SPEEDS $S"
297                    fi
298            fi
299    done
300    echo
301    
302    if [ "$GOODFAN" = "" ]
303    then
304            echo 'There are no working fan sensors, all readings are 0.'
305            echo 'Make sure you have a 3-wire fan connected.'
306            echo 'You may also need to increase the fan divisors.'
307            echo 'See doc/fan-divisors for more information.'
308            exit 1
309    fi

Link to the entire code of the above fragment: http://www.lm-sensors.org/browser/lm-se … /pwmconfig. I'm not exactly sure what the "-f2" accomplishes in the line S=`cat $i | cut -d' ' -f2`, so I don't really understand why it's assigning a "0" or "-1" to "$S". Nor can I figure why this causes my fans to stop.

If anyone might know what's going on, how I can fix it, or can just point me in the right direction I'd be grateful.

fphillips

Member

From: Austin, TX

Registered: 2009-01-24

Posts: 202

Re: pwmconfig stops fans then errors out

Did kernel 2.6.33 fix this?

http://lm-sensors.org/wiki/Configuratio … io-S4000NX
http://git.kernel.org/?p=linux/kernel/g … 281cf3d562

The hardware seems to be working fine, the driver just isn't reading fan speeds. The pwmconfig script is ok: its checking for a value of zero or -1 in fanN_input. The comment says that when there aren't two fields (columns delimited by a ' ') in the file, it returns the first field. Sysfs has only one value per file (the fan speed). It was probably procfs that had two fields, back before sysfs existed.