Issues with lm_sensors on Intel SE7501cw2

Mark Studebaker mds at
Tue Oct 21 02:17:09 CEST 2003

I agree that Super I/O detection is quite reliable and that the
confidence for these should be increased to 9.
Khali, feel free to do it if you get to it before I do.

Jean Delvare wrote:
> ** MDS, please read below **
> I definitely can't resist answering a 17.7kB report ;)
> > I have an Intel SE7501cw2 motherboard with dual 2.4 GHz processors in
> > a 1U chassis.  This motherboard has a Winbond w83627hf chip and a max
> > 6650 (or 6651) chip.
> According to the details given below, this must be a 6651, since the
> 6650 monitors a single fan.
> > Most of my fans are Sunon GM1204PQV1-8A fans, which should run at 9200
> > RPM according to the manufacturer.
> >
> > I'm running RH9 and lm_sensors 2.8.1.
> >
> > If I plug and unplug the fans, I'm able to correlate their readings
> > with sensors reports.  max6650-i2c-0-1b's four fans correspond to
> > sys3 (J29) sys4 (J30), cpu1 (J16), and cpu2 (J14), respectively.
> > w83627hf's three fans correspond to sys2 (J3), sys1 (J1), and sys5
> > (J58).  This information may be useful to someone else.
> Nice, at least you got it partly working.
> > 1. sensors-detect recommends w83781d, which doesn't seem to work, but
> > doesn't recommend w83627hf, which does seem to work.
> Already seen that. I have some proposal for a fix but definitely would
> like MDS's opinion.
> First, the w83781d driver is supposed to handle the w83627hf on the ISA
> bus, so it should be investigated why sensors-detect can detect the chip
> while the w83781 driver rejects it.
> > Driver `w83781d' (should be inserted):
> >   Detects correctly:
> >   * ISA bus address 0x0290 (Busdriver `i2c-isa')
> >     Chip `Winbond W83627HF' (confidence: 8)
> >
> > Driver `w83627hf' (may not be inserted):
> >   Misdetects:
> >   * ISA bus address 0x0290 (Busdriver `i2c-isa')
> >     Chip `Winbond W83627HF Super IO Sensors' (confidence: 8)
> Second problem. Both detections have the same confidence value, so the
> choice is left to sensors-detect - and its choice is rather arbitrary. I
> think that we believe that the w83627hf is overall better that the
> w83781d when both can be used, so what about raising the confidence to 9
> for the w83627hf driver.
> MDS, I took a look at sensors-detect and there's a single confidence (8)
> value fot all SuperIO probes. Is it a feature? If SuperIO probes are
> known to be better that other detections, let's set the confidence value
> to 9 instead, it would solve a number of problems. The other possibility
> is to move the SuperIO confidence value from the code to the data
> structure - allowing a different confidence value for each SuperIO
> detection, if that makes more sense. In this case, we would give a
> confidence value of 9 to the W83627HF and 8 to all the other ones. This
> is a change I'd be able to make by myself, still I'd like to hear your
> opinion about that. I've never worked with these SuperIO things before,
> maybe you know something I ignore.
> > [root at gb0007 lm_sensors-2.8.1]# modprobe w83781d
> > [root at gb0007 lm_sensors-2.8.1]# sensors -s
> > [root at gb0007 lm_sensors-2.8.1]# sensors
> No Winbond chip.
> > [root at gb0007 lm_sensors-2.8.1]# rmmod w83781d
> > [root at gb0007 lm_sensors-2.8.1]# modprobe w83627hf
> > [root at gb0007 lm_sensors-2.8.1]# sensors -s
> > [root at gb0007 lm_sensors-2.8.1]# sensors
> Still no Winbond chip. Strange, isn't it supposed to be there?
> > [root at gb0007 lm_sensors-2.8.1]# rmmod w83781d
> That module isn't supposed to be loaded at this moment. There's
> something unclear here, the rmmod command should return an error. Can
> you test that again, checking with lsmod which modules are loaded each
> time? Don't you have some kind of module auto-loading making trouble
> here? Taking a look at dmesg while loading/unloading the modules could
> help.
> > 2. The max6650 fan speed measurement seems to be all or nothing.  If
> > there's a (Sunon) fan connected and operational, it reports 7650RPM.
> > If there's no fan connected, it reports 0 RPM.  If I physically slow
> > the fan down, it still report 7650 RPM.  (The tachs on the w83627hf
> > sensor do show decreased rpm when I impede their fans).
> >
> > 3. The fan speeds reported (7650 or 18,000-21,000) seem to be
> > inconsistent with the advertised speeds.  Changing the divisors
> > doesn't seem to affect the reported values.
> >
> > 4. The speed control on the max6650 doesn't seem to work.  See below.
> Strange. Could be because the driver assumes too much conditions that
> aren't correct for your system. The MAX6650 driver was contributed by
> John Morris. John, could you please take a look at Mark's problem?
> > 5. The w83627hf's "pwm1" setting seems to have no effect:
> I think that PWM needs special wiring on the motherboad in order to
> work. Could it be that your motherboard doesn't have it?
> > 6. The w83627hf's "pwm2" setting is able to reduce the speed of fans 1
> > and 2, but only to about half.  I can hear them change speed when I do
> > this.  I can't get them to stop completely, though.
> This may be a feature more that a bug. Fully starting a fan requires a
> higher current. What's more, stopping a fan completely is somewhat
> dangerous, isn't it? Same as for PWM1, I think that PWM2 works thank to
> adequate wiring on your motherboard, but maybe the wiring and
> electronics are such that the W83627HF isn't allowed to lower the fan
> speed below a given threshold.
> That said, please note that I did not write the w83627hf driver (nor the
> max6650 driver, for that matter) so I'm just guessing. Our drivers still
> may be buggy, so if you are willing to read the code and compare with
> the datasheets, feel free to do so and report errors if you find some.
> > 7.  Changes to the "pwm2" setting seem to be transient.  Something
> > happens to change it back to 255.
> >
> > [root at oscarnode001 root]# cat
> > /proc/sys/dev//sensors/w83627hf-isa-0290/pwm2     0 1
> > [root at oscarnode001 root]# sleep 60
> > [root at oscarnode001 root]# cat
> > /proc/sys/dev//sensors/w83627hf-isa-0290/pwm2     255 1
> Don't you by any chance have a monitoring daemon running on the machine?
> > 8. Sometimes the "lm75" module loads and detects something.  I'm not
> > aware of there being any lm75's or compatible devices on this system.
> > (...)
> > 9. The lm75's temperature readings are bogus.  At an earlier point I
> > got them to report reasonable values, but I can't get back to that
> > state.
> Could you provide the output of "i2cdetect 0"? I'd also be interested in
> the output of "i2cdump 0 0x1f" since you seem to have an unknown chip
> there.
> Strangely, sensors-detect didn't report any client found at these
> addresses (0x48 and 0x49). Could you run sensors-detect again (unload
> all client drivers first) and see if it now does? These LM75s could
> actually be emulated by your w83627hf, although it's unusual to see this
> behavior when the w83627hf itself is on the ISA (as opposed to I2C) bus.
> > 10.  The default value for the sensor type on the  w83627hf's
> > temperature sensor, according to sensors.conf, is thermistor (3435).
> > But for me it seems to be defaulting to "1", PII/Celeron Diode.
> The "defaults" might be confusing, I agree. This refers to power-up
> default for the chip. The BIOS may then reconfigure the chip during the
> boot process. I believe that this is what has happened there.
> If you believe that we should say the things differently in the
> configuration file, suggestions are welcome.
> Thanks for the long and detailed report. I doubt we'll be able to
> quickly solve all the problems you encountered, since there are many,
> still this will help us if similar problems are reported in the future,
> plus I hope I clarified some points.
> --
> Jean Delvare

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