Hi Mike, Joe - It looks like the scx200_acb driver scans two IO addresses by default (0x820, 0x840). One of them doesn't exist. That explains the ACBCTL2 readback problem. =) You should be able to get rid of that message by using the 'base' module parameter. Here's a guess at the format. $ modprobe scx200_acb base=0x820,0 In [1], Joe mentioned a 15 second delay. The scx200_acb driver has a flaw where it misses the NACK indication when it tries to write to an address that doesn't exist. This causes it to timeout instead of immediately returning a failure. Likely, your hardware is 'scanning' for around 15 devices that don't exist. Refer to this patch for a possible fix: http://lists.lm-sensors.org/pipermail/lm-sensors/2005-December/014716.ht ml Another thing to do is to add 'ignore' parameters to modprobe so that the chip drivers don't scan for devices that don't exist. For example, I use this for my lm83: $ modprobe lm83 force=0,0x4c ignore=0,0x18,0,0x19,0,0x1a,0,0x29,0,0x2a,0,0x2b,0,0x4d,0,0x4e Ben > -----Original Message----- > From: lm-sensors-bounces at lm-sensors.org > [mailto:lm-sensors-bounces at lm-sensors.org] On Behalf Of > Michael Renzmann > Sent: Tuesday, January 03, 2006 1:53 AM > To: lm-sensors > Subject: scx200_acb: unexpected ACBCTL2 readback > > Hi. > > On the voyage-linux mailing list there recently has been a > report about > a problem related to scx200_acb in 2.6.x kernels. The > original report is > at [1], a short but more detailed analysis of the problem is at [2]. > > The problem seems to be that loading scx200_acb fails during > the probing > phase, but loading and using LM77 after that still works fine. Quoting > [2]: > > === cut === > Same here with a non-voyage 2.6.11 kernel. I enabled > debugging and added > a bit more info into the relevant message and I get: > > i2c /dev entries driver > scx200_acb: ACBCTL2 readback failed, got 0xff > : probe failed > > The driver write 0x70 to ACBCTL2 and expects to read 0x70 back, but it > gets 0xff instead. Looked into the manual briefly, but seems too > complicated to figure out quickly. As you mention, lm77 works fine > thereafter. Weird... > === cut === > > Comments? > > Bye, Mike > > [1] > http://list.voyage.hk/pipermail/voyage-linux/2005-December/000548.html > [2] > http://list.voyage.hk/pipermail/voyage-linux/2006-January/000565.html > > > _______________________________________________ > lm-sensors mailing list > lm-sensors at lm-sensors.org > http://lists.lm-sensors.org/mailman/listinfo/lm-sensors > >
