Re: [RESEND v2] iommu/vt-d: Use passthrough mode for the Intel IPUs

From: Sakari Ailus
Date: Tue Apr 20 2021 - 07:02:15 EST


Hi Bingbu,

On Tue, Apr 20, 2021 at 06:34:26PM +0800, Bingbu Cao wrote:
> Andy,
>
> On 4/20/21 6:20 PM, Andy Shevchenko wrote:
> > On Tue, Apr 20, 2021 at 10:48:33AM +0800, Bingbu Cao wrote:
> >> Intel IPU(Image Processing Unit) has its own (IO)MMU hardware,
> >> The IPU driver allocates its own page table that is not mapped
> >> via the DMA, and thus the Intel IOMMU driver blocks access giving
> >> this error:
> >>
> >> DMAR: DRHD: handling fault status reg 3
> >> DMAR: [DMA Read] Request device [00:05.0] PASID ffffffff
> >> fault addr 76406000 [fault reason 06] PTE Read access is not set
> >>
> >> As IPU is not an external facing device which is not risky, so use
> >> IOMMU passthrough mode for Intel IPUs.
> >>
> >> Fixes: 26f5689592e2 ("media: staging/intel-ipu3: mmu: Implement driver")
> >> Signed-off-by: Bingbu Cao <bingbu.cao@xxxxxxxxx>
> >> ---
> >> drivers/iommu/intel/iommu.c | 29 +++++++++++++++++++++++++++++
> >
> > This misses the changelog from v1 followed by the explanation why resent.
> >
> I noticed there was a typo in the recipient list:
> stable.vger.kernel.org -> stable@xxxxxxxxxxxxxxx
>
> no code change for resent.

When you're submitting a patch and want it reach the stable kernels, you'll
need to add a Cc tag:

Cc: stable@xxxxxxxxxxxxxxx

But not actually add the address to cc. I dropped stable@vger address from
distribution.

Please change this for v3.

--
Kind regards,

Sakari Ailus