ACK: [SRU][J][PATCH 0/1] disable Intel DMA remapping by default

[Mauricio Faria de Oliveira]

Unfortunately, it seems there's impact to storage controllers as well
(bug 1970453, workaround intel_iommu=off), with data corruption
reported (comment #6).

On Thu, May 5, 2022 at 11:29 PM Kai-Heng Feng
<kai.heng.feng at canonical.com> wrote:
>
> Maybe use INTEL_IOMMU_BROKEN_GFX_WA instead? The option can let GFX
> devices identity mapped while keep IOMMU on for other devices.
>
> Kai-Heng
>
> On Fri, May 6, 2022 at 2:04 AM Zachary Tahenakos
> <zachary.tahenakos at canonical.com> wrote:
> >
> > Acked-by: Zachary Tahenakos <zachary.tahenakos at canonical.com>
> >
> > On 5/5/22 8:34 AM, Andrea Righi wrote:
> > > BugLink: https://bugs.launchpad.net/bugs/1971699
> > >
> > > [Impact]
> > >
> > > It seems that enabling Intel IOMMU can cause some weird gfx problems,
> > > see for example:
> > >
> > >   https://bugs.launchpad.net/bugs/1971146
> > >   https://bugs.launchpad.net/bugs/1965882
> > >
> > > [Test case]
> > >
> > > We don't have any specific test case, only other bug reports that
> > > tracked down the origin of the issue as being introduced when
> > > CONFIG_INTEL_IOMMU_DEFAULT_ON has been enabled by default.
> > >
> > > [Fix]
> > >
> > > Revert "UBUNTU: [Config] enable Intel DMA remapping options by default"
> > >
> > > [Regression potential]
> > >
> > > DMA remapping device not present at boot by default, users that require
> > > this feature will need to specifically add intel_iommu=on to the kernel
> > > boot parameters to enable it.
> > >
> > >
> >
> > --
> > kernel-team mailing list
> > kernel-team at lists.ubuntu.com
> > https://lists.ubuntu.com/mailman/listinfo/kernel-team
>
> --
> kernel-team mailing list
> kernel-team at lists.ubuntu.com
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-- 
Mauricio Faria de Oliveira