Hi Jean, On Wed, 11 June 2008 Jean Delvare <khali at linux-fr.org> wrote: > Hi Bruno, > > On Sun, 8 Jun 2008 22:30:51 +0200, Bruno Pr?mont wrote: > > Now I'm running 2.6.25.5 with both patches (the one changing > > excessively large values to 0 and automatic fan control) > > > > ------ FAN connected to W83697HG ------ > > Looking at power and speed signals with an oscilloscope I get: > > - slightly above 12V for FAN power > > - speed square signal is about 11V at 62.5Hz > > > > Both fan power and fan speed signal show a noise of about 0.1V in > > saw shape ( |\|\|\|\ ) at 4kHz. > > > > Changing value for pwm1_enable, pwm1_freq and pwm1 does not > > influence the fan at all (no voltage variation, no variation in > > noise). So this mainboard does not support FAN control :( > > > > The W83697HG reports a speed of 1750 RPM though I think it's a > > slightly high (Sticker on FAN says 1000RPM ... 2500RPM) > > Most fans emit two pulses per revolution, so 62.5 Hz means 1875 RPM. > 1750 RPM isn't too far away, so I'd say it's correct. Ok, good to know that there are two pulses per revolution. Need to verify the FAN's datasheet for temperature-speed mappings... > > Connecting the FAN to the board's (LE-365) power-out connector > > produces exactly the same results, thus the noise is generalized > > for the board's "12V rail" > > ------ END ------ > > > > Note: after connecting a second (non-controlled) fan to the > > mainboard (on second fan connector) the W83697HG stopped reporting > > the bad values and did not start reporting them even after > > disconnecting the second fan (no system shutdown/reboot during the > > whole testing) > > > > The second FAN shows the same voltages, just with different > > frequency for the speed signal. > > > > > > ------ FAN connected to IT8712F ------ > > (only speed sensor, power taken directly from system's power supply) > > > > Looking at power and speed signals with an oscilloscope I get: > > - slightly above 12V for FAN power > > - speed square signal is about 5V at 55Hz > > > > The IT8712F reports a speed of 4600 RPM though visually FAN does > > not spin more quickly. 4600 RPM is definitely too much... > > I don't think you can judge the speed of a fan by just looking at it > (if you are a human being.) Your hears will tell you more than your > eyes about a fan's speed. There is a sticker in the middle of the rotor of the fan, the sticker not being properly centered one can compare quick and slow based on how smoothed the sticker looks like, but sure ears cqn better make distinction and eventually also determine the frequency if good enough at music (+ knowing what frequency corresponds to what note) > 55 Hz would be 1650 RPM. If the IT8712F reports 4600 RPM then it's > indeed certainly wrong. Can you check what speed is reported in the > BIOS? Please also test with another fan if you can. I'd like to know > if that's a problem with this specific fan (in which case there's > probably not much we can do) or not. I suspect not (see below.) I've not checked the BIOS yet but increasing divider helps - see also below I have a second FAN of the same brand, same model which produces equivalent values. I didn't check a quicker fixed-speed fan yet on that connector. The CPU fan is fixed-speed and regulated by IT8712F (speed reported as 3200 with pwm=2 RPM, about 4400 RPM with pwm=4 - same values for divider = 2..8) By the way, how does this behave with S3 (suspend to RAM), are all values reprogrammed by the kernel or is it userspace's job (can't test because of the graphics chips... no resume support yet in kernel for ATI/AMD graphics) I know that on older nforce-based PC did forget pwm settings on resume (never cared about the divider so would have to verify for that one) > > > > PS: This mainboard (IEI Kino690S) is capable to regulating FAN > > speed all its fan connectors > > ------ END ------ > > > > > > I will look if I can find a way do determine the real fan speed in > > order to compare with the values both chips report. > > Looks like IT8712F (divisor = 2) reports a speed 3 times higher than > > W83697HG (divisor = 4) > > Please remember that the divisor value does _not_ divide the speed > value. It only affects the range of measurable values. For a fan that > could run as slow as 1000 RPM, you want to set the divider to 8. Changing the divider to 8 makes the IT8712F report a likely speed around 1500 RPM, so the divider was the cause of the bad value. (wondering why it defaults to such a small divider as is 2) > > I guess the different voltages seen for both on speed line is due to > > different resistors on the chips or the circuit in front of them. > > Can you tell us what revision of the IT8712F you have? The it87 driver > will write it to the kernel log when you load it. I would also like a > dump of the chip (using isadump). According to dmesg it's revision 8: [ 26.954326] i2c /dev entries driver [ 26.954524] it87: Found IT8712F chip at 0xe80, revision 8 [ 26.954572] it87: in3 is VCC (+5V) [ 26.954611] it87: in7 is VCCH (+5V Stand-By) Not sure how to call isadump to get the right data, its man-page is reasonably vague regarding the addrreg and datareg args... sould it be the following?: isadump 0xe85 0xe86 > Recent IT8712F chips have 16-bit tachometer registers, but the it87 > driver doesn't support this mode for that chip yet. We received a > patch adding support for that 4 months ago: > http://lists.lm-sensors.org/pipermail/lm-sensors/2008-February/022460.html > I reviewed it, it needed some more work, but the author never followed > up. If you need this, I guess we'll have to revive it. I could help testing that patch though test-responsiveness may not be optimal knowing that this host is actively used and freeing a timeslot for testing is not that easy (usually only possible at night during weekend) Bruno
