Messages in this thread | | | Date | Sat, 10 Jan 2009 00:45:31 +0800 | From | "Zhao, Yu" <> | Subject | Re: git-latest: kernel oops in IOMMU setup |
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Dirk Hohndel wrote: > On Sat, 10 Jan 2009 00:16:22 +0800 > "Zhao, Yu" <yu.zhao@intel.com> wrote: > >> Dirk Hohndel wrote: >>> On Fri, 9 Jan 2009 14:53:14 +0800 >>> "Han, Weidong" <weidong.han@intel.com> wrote: >>> >>>> Dirk Hohndel wrote: >>>>> On Thu, 8 Jan 2009 18:05:15 -0800 >>>>> Dirk Hohndel <hohndel@infradead.org> wrote: >>>>> >>>>>> On Fri, 9 Jan 2009 08:58:46 +0800 "Han, Weidong" >>>>>> >>>>>> I updated to Linus' latest git (as your description made me >>>>>> wonder if the async stuff might play a role here). I still get >>>>>> an oops - but at a different spot and the system no longer hangs >>>>>> - it partly recovers (but things aren't too well - for example >>>>>> my USB keyboard / mouse don't work anymore). >>>>> Spoke too soon. Rebooted and had the same hard lockup again. This >>>>> time I had my camera within reach, so here's the trace: >>>>> >>>>> device_to_iommu+0x33/0x73 >>>>> domain_context_mapping_one+0x37/0x335 >>>>> domain_context_mapping+0x25/0xa7 >>>>> iommu_prepare_identity+0xd7/0xf3 >>>>> intel_iommu_init+0x4e4/0x8f3 >>>>> ? mutex_lock >>>>> ? sysctl_net_init >>>>> ? pci_iommu_init >>>>> pci_iommu_init >>>>> >>>>> I also have stack, code and register values. Let me know if you >>>>> need them. Or I can just post the picture :-) >>>>> >>>>> Again, very latest git tree, VT-d enabled. >>>>> >>>>> /D >>>> I tried latest git tree, it works for me. Above call trace looks >>>> right. >>> Spent some more time reading the code. Can't quite claim to >>> understand all of it, yet, but I notice that most everywhere else >>> drhd->devices[i] is checked to be != NULL before it is accessed. >>> Why is it safe not to do that in device_to_iommu()? >>> >>> Would the patch below be a valid fix? It stops my system from >>> hanging at boot. But I wonder if there is an assertion that if >>> drhd->ignored is 0 then drhd->devices[0..drhd->device_cnt] is known >>> to be != NULL and therefore this test is just hiding a bug >>> somewhere else... >>> >>> /D >>> >>> Signed-off-by: Dirk Hohndel <hohndel@linux.intel.com> >>> --- >>> drivers/pci/intel-iommu.c | 3 ++- >>> 1 files changed, 2 insertions(+), 1 deletions(-) >>> >>> diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c >>> index 235fb7a..3dfecb2 100644 >>> --- a/drivers/pci/intel-iommu.c >>> +++ b/drivers/pci/intel-iommu.c >>> @@ -438,7 +438,8 @@ static struct intel_iommu *device_to_iommu(u8 >>> bus, u8 devfn) continue; >>> >>> for (i = 0; i < drhd->devices_cnt; i++) >>> - if (drhd->devices[i]->bus->number == bus && >>> + if (drhd->devices[i] && >>> + drhd->devices[i]->bus->number == bus && >>> drhd->devices[i]->devfn == devfn) >>> return drhd->iommu; >>> >> Did you see following in the kernel message? >> printk(KERN_WARNING PREFIX >> "Device scope device [%04x:%02x:%02x.%02x] not >> found\n", segment, scope->bus, path->dev, path->fn); >> >> If yes, then >> Acked-by: Yu Zhao <yu.zhao@intel.com> > > Yes, > > DMAR: Device scope device [0000:00:03:02] not found > DMAR: Device scope device [0000:00:03:02] not found > DMAR: Device scope device [0000:00:03:03] not found > DMAR: Device scope device [0000:00:03:03] not found
The laptop has a nasty bios, try to update it if you want to get rid of these noises... assuming you are luck enough :-)
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