Re: [Issue]platform/x86: iommu: System can't shutdown because iommu driver keeps checking the status of DMA_GSTS_TES

From: Lu Baolu
Date: Tue Jun 30 2020 - 03:52:47 EST


Hi Koba,

On 2020/6/30 15:31, Koba Ko wrote:
On Mon, Jun 15, 2020 at 3:20 PM Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote:

Hi Koba Ko,

On 2020/6/15 11:19, Koba Ko wrote:
hi All,
I have a machine and there's only intel gpu.
the secureboot and vt-d is enabled in BIOS.
On the Ubuntu desktop, I do s2idle first and restart the machine.
The machine can't restart successfully, so I need to press the
power button to shutdown.
I tried each of the following and the issue can't be triggered.
1. disable secure boot in BIOS.
2. intel_iommu=off.
3. intel_iomm=igfx_off.
4. nomodeset
5. i915.modeset=0.

After I investigate further, find inte_iommu keeps checking the status
of DMA_GSTS_TES.
During the procedure of restart, the driver would disable iommu
translation and
check status of DMA_GSTS_TES until status of DMA_GSTS_TES is 0.

If you need more information, I can provide it.

Do you mind telling what platform is it?

Best regards,
baolu
Hi Baolu,
Sorry, i missed your email.
I'm running on TGL.
My colleague has reported this on bugzilla.
Have tested your patch and it works fine.
https://bugzilla.kernel.org/show_bug.cgi?id=208363

Could you explain more about these patches!? Why do we need a flag
for active iommu!?


We're still investigating this issue. If we find out more, I'll let you
know. Thanks a lot for the reporting.

Best regards,
baolu