Re: [PATCH 1/1] iommu/vt-d: Skip TE disabling on quirky gfx dedicated iommu

[Lu Baolu]

On 7/22/20 7:45 AM, Limonciello, Mario wrote:
> > -----Original Message-----
> > From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Sent: Tuesday, July 21, 2020 6:07 PM
> > To: Limonciello, Mario; Joerg Roedel
> > Cc: baolu.lu@xxxxxxxxxxxxxxx; Ashok Raj; linux-kernel@xxxxxxxxxxxxxxx;
> > stable@xxxxxxxxxxxxxxx; Koba Ko; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
> > Subject: Re: [PATCH 1/1] iommu/vt-d: Skip TE disabling on quirky gfx dedicated
> > iommu
> >
> >
> > [EXTERNAL EMAIL]
> >
> > Hi Limonciello,
> >
> > On 7/21/20 10:44 PM, Limonciello, Mario wrote:
> > > > -----Original Message-----
> > > > From: iommu<iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx>  On Behalf Of Lu
> > > > Baolu
> > > > Sent: Monday, July 20, 2020 7:17 PM
> > > > To: Joerg Roedel
> > > > Cc: Ashok Raj;linux-kernel@xxxxxxxxxxxxxxx;stable@xxxxxxxxxxxxxxx; Koba
> > > > Ko;iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
> > > > Subject: [PATCH 1/1] iommu/vt-d: Skip TE disabling on quirky gfx dedicated
> > > > iommu
> > > >
> > > > The VT-d spec requires (10.4.4 Global Command Register, TE field) that:
> > > >
> > > > Hardware implementations supporting DMA draining must drain any in-flight
> > > > DMA read/write requests queued within the Root-Complex before completing
> > > > the translation enable command and reflecting the status of the command
> > > > through the TES field in the Global Status register.
> > > >
> > > > Unfortunately, some integrated graphic devices fail to do so after some
> > > > kind of power state transition. As the result, the system might stuck in
> > > > iommu_disable_translation(), waiting for the completion of TE transition.
> > > >
> > > > This provides a quirk list for those devices and skips TE disabling if
> > > > the qurik hits.
> > > >
> > > > Fixes:https://bugzilla.kernel.org/show_bug.cgi?id=208363
> > > That one is for TGL.
> > >
> > > I think you also want to add this one for ICL:
> > > Fixes:https://bugzilla.kernel.org/show_bug.cgi?id=206571
> >
> > Do you mean someone have tested that this patch also fixes the problem
> > described in 206571?
>
> Yes, confusingly https://bugzilla.kernel.org/show_bug.cgi?id=208363#c31 actually
> is the XPS 9300 ICL system and issue.
>
> I also have a private confirmation from another person that it resolves it for
> them on another ICL platform.

Okay! Thank you very much! I just posted v2 with this tag added.

Best regards,
baolu