Fan control for new PowerMac G5 2.7GHz machines?

[Brian D. Carlstrom]

Benjamin Herrenschmidt writes:
 > > i2c /dev entries driver
 > > /u3 at 0,f8000000/i2c at f8001000: Missing interrupt or address !
 > > 
 > > In therm_pm72_attach() it hits 'Found K2', but u3_0 and u3_1 
 > > are never set, so start_control_loops() is never called.
 > > 
 > > I'll look at it more when I have some time.
 > 
 > Ah yes, this is indeed the problem ! There is a bug in Apple device tree
 > on these machines that is breaking Linux. I should have a workaround
 > upstream, but for some reason, it seems it's not working for you.

Well, I have good news and bad news. I switched from the patched YDL
2.6.10-1 to linux-stable 2.6.12.3 to debug the fan issue. 

The good news is that my fans control now works. Since Geoff is having
problems, I'll include my DBG output from therm_pm72 below. For me it
is reporting "found U3-1, attaching FCU" and not "Found K2".

The bad news is that ybin is having trouble:

    # ybin
    ofpath: /proc/device-tree is broken.  Do not use BootX to boot, use yaboot.
    ofpath: The yaboot HOWTO can be found here: http://www.alaska.net/~erbenson/doc
    ybin: Unable to find OpenFirmware path for boot=/dev/sda2
    ybin: Please add ofboot=<path> where <path> is the OpenFirmware path to /dev/sda2 to /etc/yaboot.conf

I've heard a newer yaboot might fix this but for now I just booted to my
old kernel to update yaboot.conf.

-bri

found U3-0
counted 2 CPUs in the device-tree
Liquid cooling pumps detected, using new algorithm !
CPU 0 Using 6 power history entries
CPU 1 Using 6 power history entries
all control loops up !
found U3-1, attaching FCU
FCU attached
everything up, starting control loops
main_control_loop started
Found KeyWest i2c on "u3", 2 channels, stepping: 4 bits
ADC config reg: 00
ADC config reg: 00
  cpu 0, exhaust RPM: 1000
  cpu 0, temp raw: 01f2, m_diode: 9fc5, b_diode: fffff67d
  temp: 39.653
  cpu 0, current: 17.333, voltage: 1.413, power: 24.502 W
  cpu 1, exhaust RPM: 1000
  cpu 1, temp raw: 01e9, m_diode: 9dbb, b_diode: fffff674
  temp: 37.134
  cpu 1, current: 19.409, voltage: 1.408, power: 27.341 W
  power target: 85.000, error: 57.658
  integral: 0159f366
   integ_p: 29
   adj_in_target: 53.594, ttarget: 81
   deriv_p: 0
   prop_p: -140
   sum: -140
** CPU 1 RPM: 860 Ex, 834, Pump: 1250, In, overtemp: 0
backside:
  current pwm: 26
  temp: 49.000, target: 75.000
  integral: fefc0000
   integ_p: 0
   deriv_p: 0
   prop_p: -130
   sum: -130
** BACKSIDE PWM: 20
drives:
  current rpm: 1000
  temp: 21.500, target: 40.000
  integral: ff470000
   integ_p: 0
   deriv_p: 0
   prop_p: -93
   sum: -93
** DRIVES RPM: 907