[PATCH v2] iommu/arm-smmu-qcom: Add missing GMU entry to match table

Johan Hovold johan at kernel.org
Mon Dec 11 02:11:29 PST 2023


On Sun, Dec 10, 2023 at 10:06:53AM -0800, Rob Clark wrote:
> From: Rob Clark <robdclark at chromium.org>
> 
> In some cases the firmware expects cbndx 1 to be assigned to the GMU,
> so we also want the default domain for the GMU to be an identy domain.
> This way 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 later 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.
> 
> Cc: stable at vger.kernel.org
> Signed-off-by: Rob Clark <robdclark at chromium.org>

Tested-by: Johan Hovold <johan+linaro at kernel.org>



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