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

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Date:   Tue, 30 Jun 2020 15:52:40 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     Koba Ko <koba.ko@...onical.com>
Cc:     baolu.lu@...ux.intel.com, David Woodhouse <dwmw2@...radead.org>,
        Joerg Roedel <joro@...tes.org>,
        iommu@...ts.linux-foundation.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Kai Heng Feng <kai.heng.feng@...onical.com>,
        "Raj, Ashok" <ashok.raj@...el.com>,
        "Sun, Jian" <jian.sun@...el.com>
Subject: Re: [Issue]platform/x86: iommu: System can't shutdown because iommu
 driver keeps checking the status of DMA_GSTS_TES

Hi Koba,

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