On 11-04-15 09:11 AM, 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> > --- > arch/x86/include/asm/msr-index.h | 4 ++++ > arch/x86/kernel/cpu/amd.c | 19 +++++++++++++++++++ > 2 files changed, 23 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h > index fd5a1f3..3cce714 100644 > --- a/arch/x86/include/asm/msr-index.h > +++ b/arch/x86/include/asm/msr-index.h > @@ -96,11 +96,15 @@ > #define MSR_IA32_MC0_ADDR 0x00000402 > #define MSR_IA32_MC0_MISC 0x00000403 > > +#define MSR_AMD64_MC0_MASK 0xc0010044 > + > #define MSR_IA32_MCx_CTL(x) (MSR_IA32_MC0_CTL + 4*(x)) > #define MSR_IA32_MCx_STATUS(x) (MSR_IA32_MC0_STATUS + 4*(x)) > #define MSR_IA32_MCx_ADDR(x) (MSR_IA32_MC0_ADDR + 4*(x)) > #define MSR_IA32_MCx_MISC(x) (MSR_IA32_MC0_MISC + 4*(x)) > > +#define MSR_AMD64_MCx_MASK(x) (MSR_AMD64_MC0_MASK + (x)) > + > /* These are consecutive and not in the normal 4er MCE bank block */ > #define MSR_IA32_MC0_CTL2 0x00000280 > #define MSR_IA32_MCx_CTL2(x) (MSR_IA32_MC0_CTL2 + (x)) > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > index 3ecece0..3532d3b 100644 > --- a/arch/x86/kernel/cpu/amd.c > +++ b/arch/x86/kernel/cpu/amd.c > @@ -615,6 +615,25 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) > /* As a rule processors have APIC timer running in deep C states */ > if (c->x86 >= 0xf && !cpu_has_amd_erratum(amd_erratum_400)) > set_cpu_cap(c, X86_FEATURE_ARAT); > + > + /* > + * Disable GART TLB Walk Errors on Fam10h. We do this here > + * because this is always needed when GART is enabled, even in a > + * kernel which has no MCE support built in. > + */ > + if (c->x86 == 0x10) { > + /* > + * BIOS should disable GartTlbWlk Errors themself. If > + * it doesn't do it here as suggested by the BKDG. > + * > + * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012 > + */ > + u64 mask; > + > + rdmsrl(MSR_AMD64_MCx_MASK(4), mask); > + mask |= (1 << 10); > + wrmsrl(MSR_AMD64_MCx_MASK(4), mask); > + } > } > > #ifdef CONFIG_X86_32 Ok, I'll test it today. Should I apply it on a clean rc3 without any of the other patches? BTW, may I suggest adding the info under bug 33012 in kernel bugzilla? This could be useful in the future. I'll keep you up to date. -- Alexandre Demers _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
