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 > > 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? > Can somebody with the same device trigger this crash too (greped LKML 2001-2008, found nothing)? And to answer this question: with the same device (except that it's at 01.3 instead of 07.3 here), none of the 3 above commands crash my system (kernel 2.6.29.) -- 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
