On Fri, Apr 15, 2011 at 03:11:52PM +0200, Joerg Roedel wrote: > On Wed, Apr 13, 2011 at 07:33:40PM -0700, Linus Torvalds wrote: > > we definitely want to also understand the reason for things not > > working, even if we do revert.. > > Okay, here it is. > > After experimenting with different configurations for the north-bridge > it turned out that a GART related MCE fires at the time the machine > reboots. BIOSes configure the machine to sync-flood in that case which > causes a reboot. > > After decoding the MCE it turned out to be a GART TBL Wlk Error. Such > errors can happen if devices (speculativly) access GART ranges mapped > invalid. The AMD BKDG for Fam10h CPUs recommends to disable these errors > at all. But unfortunatly some BIOSes (including the one on my laptop) > forget to do this. > > Below is a patch which disables these errors if the BIOS didn't do it. > It fixes the problem on my site. > > Alexandre, can you try this patch on your machine too, please? > > Regards, > > Joerg > > From aaacff8db50b6ed4345e337ecbe53e505699c7e5 Mon Sep 17 00:00:00 2001 > From: Joerg Roedel <joerg.roedel@xxxxxxx> > Date: Fri, 15 Apr 2011 14:47:40 +0200 > Subject: [PATCH] x86/amd: Disable GartTlbWlkErr when BIOS forgets it > > This patch disables GartTlbWlk errors on AMD Fam10h CPUs if > the BIOS forgets to do is (or is just too old). Letting > these errors enabled can cause a sync-flood on the CPU > causing a reboot. > > This patch is the fix for > > https://bugzilla.kernel.org/show_bug.cgi?id=33012 > > on my machine. > > Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx> Joerg, What about tagging this patch for stable/longterm releases? Potentially there are other cases where certain combinations of hardware(GPUs)/drivers/whatsoever might trigger a GartTlbWlkErr. If the BIOS doesn't follow the BKDG recommendation to mask these errors, the system will hang/reboot. Thus I think having this quirk in .32 and .38 (at least) is useful. Andreas _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
