Most recent kernel where this bug did not occur:
Distribution: Ubuntu kernel 220.127.116.11 or see below
Hardware Environment: ASUS P5K SE , 4x1GB memory
Software Environment: Ubuntu/Debian sid
I've bought recently new motherboard - ASUS P5K SE. It contains
W83627DHG sensor chip.
Everything was working fine using 18.104.22.168 kernel except IDE chip
(marvel). So I've upgraded to 22.214.171.124. And here the story begins.
After modprobed w83627ehf I received:
w83627ehf: Found W83627DHG chip at 0x290
w83627ehf w83627ehf.656: Setting VID input voltage to TTL
w83627ehf w83627ehf.656: VID pins in output mode, CPU VID not available
I was able to read voltage, fan temperature etc. However after I've
tried to reboot, at the end of reboot procedure the computer powered
itself off (fans stopped working), then 5 seconds later it powered
itself on but screen was blank. Only fans, disks were working.
Unplugging power cord,resetting, didn't help.
After long (long) fight of switching hardware, clearing cmos etc I've
found shortest way to unbrick my computer:
After I've removed memory dimms from first and second slot, I was able
to boot, but computer was showing strange memory amount. It should show
2048MB but the test stopped at 1308MB (or other random number, lower
that total memory amount). After pushing the reset button the amount of
memory was finally correct and I was able to insert again memory in
first and second slot. Then the computer showed finally 4096MB of memory
and I was able to boot my system up.
The problem is 100% repeatable. I was able to pinpoint problem to patch
from 2007-07-19, added to kernel tree, titled:
hwmon/w83627ehf: Add support for the VID inputs.
The version of w83627ehf before this patch works fine (compiled on 126.96.36.199 kernel).
Steps to reproduce:
1. Load newest w83627ehf on Asus P5k SE
Thanks Adam for the very good bug report. I'll attach a fix shortly.
Created attachment 14184 [details]
Be more careful when changing VID input level
Adam, please test the attached patch and report if it reliably fixes the bug.
Created attachment 14190 [details]
Be more careful when changing VID input level (v2)
Updated patch, only touch the VID level on the W83627EHF/EHG. The W83627DHG is more complex in this respect and I don't want to risk to mess it up.
Both patches works fine fine on clean 188.8.131.52. The problem is fixed.
Mark, this patch needs to go into 2.6.24 before final, and then into 2.6.23-stable.
The patch made it into Linus' tree by now:
I'll submit it for 2.6.23-stable.