On Tue, 22 Sep 2009 17:46:10 +0200, Henrik Kretzschmar wrote: > Hi there, > > at boot time my system (Wincor/Nixdorf Beetle D1) sometimes crashs while loading the i2c-piix4 driver. > I found out that I can always trigger the crash as root, which one of those: > > # hexdump -C /proc/bus/pci/00/07.3 > # hexdump -C /sys/bus/pci/devices/0000:00:07.3/config > # lspci -s 07.3 -xxx Does this crash happens even is i2c-piix4 hasn't been ever loaded since the last cold boot of the machine? > > While initialization the i2c-piix4 driver does two reads to the config space, at 0xd2 and 0xd6, > in a relative short time. That sometimes triggers the crash, > but isn't that precise like one of those commands. > > While my investigations I put a printk() between those two reads and had no more crashs > on module loading. I tested that with a script, doing insmod/rmmod 100 times in a row. > > But printk() can't be the solution, so I tried msleep(1) and udelay(250), > but with each of these my system crashed. > The time for the read and one printk() takes ~100 us on my machine, > so both time values should be more than enough, if time would have been the reason. > > Does someone have an idea what the driver should do between those two reads, to avoid crashing? I doubt we can do anything reliable in the i2c-piix4 driver itself, as this seems to be a rare hardware issue. > Can somebody with the same device trigger this crash too (greped LKML 2001-2008, found nothing)? You're rather search the lm-sensors list archives. I don't remember anything like this, but OTOH the hardware must be so old that I doubt many people are still using it. > I have another box with this device and I'll test this in 4 hours. > Or is just my Hardware broken and I should blacklist the module? That would be my bet, yes. > > I used 2.6.26-2 (deb/lenny) and 2.6.31 (vanilla) whith the same results. > If there _any_ kernel that did not exhibit the problem? > Btw, I also tried: > > $ for i in `seq 300`; do sensors; done > > which brought the same machine down (only 2.6.31) with an: > > do_IRQ: 0.66 No irq handler for vector (irq -1) > > > #lspci -s 07.3 -vvvn > > 00:07.3 0680: 8086:7113 (rev 02) That's a pretty old chip... I have one in a 1997 machine. Presumably you can easily find a replacement machine, ten times more powerful, for cheap. It might be a more constructive approach that trying to keep the old thing running. > Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- > Interrupt: pin ? routed to IRQ 9 This "?" looks rather suspicious. Smells like an IRQ routing issue? > Kernel driver in use: piix4_smbus > Kernel modules: i2c-piix4 -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
