Re: [PATCH] iommu/arm-smmu-qcom: Add missing GMU entry to match table

[Johan Hovold]

On Thu, Dec 07, 2023 at 01:24:39PM -0800, Rob Clark wrote:
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
> 
> We also want the default domain for the GMU to be an identy domain,
> so it does not get a context bank assigned.  Without this, both
> of_dma_configure() and drm/msm's iommu_domain_attach() will trigger
> allocating and configuring a context bank.  So GMU ends up attached
> to both cbndx 1 and cbndx 2.  This arrangement seemingly confounds
> and surprises the firmware if the GPU later triggers a translation
> fault, resulting (on sc8280xp / lenovo x13s, at least) in the SMMU
> getting wedged and the GPU stuck without memory access.

This sounds like something that should be backported. Should you add a
Fixes and CC-stable tag?
 
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>

Johan