Dirk Hohndel wrote:
On Fri, 9 Jan 2009 14:53:14 +0800
"Han, Weidong" <weidong.han@xxxxxxxxx> wrote:
Dirk Hohndel wrote:
On Thu, 8 Jan 2009 18:05:15 -0800
Dirk Hohndel <hohndel@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx>
---
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@xxxxxxxxx>
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