commit afc95681c3068956fed1241a1ff1612c066c75ac upstream.
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@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20231210180655.75542-1-robdclark@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2842208cc8