This is a note to let you know that I've just added the patch titled
drm/msm: Be more shouty if per-process pgtables aren't working
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-msm-be-more-shouty-if-per-process-pgtables-aren-.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit eb780db2bbf15645797db0c57fdad93a018a8b71
Author: Rob Clark <robdclark@xxxxxxxxxxxx>
Date: Tue May 16 15:20:37 2023 -0700
drm/msm: Be more shouty if per-process pgtables aren't working
[ Upstream commit 5c054db54c43a5fcb5cc81012361f5e3fac37637 ]
Otherwise it is not always obvious if a dt or iommu change is causing us
to fall back to global pgtable.
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/537359/
Link: https://lore.kernel.org/r/20230516222039.907690-2-robdclark@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index a54ed354578b5..ef4da3f0cd22d 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -157,7 +157,12 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
/* Get the pagetable configuration from the domain */
if (adreno_smmu->cookie)
ttbr1_cfg = adreno_smmu->get_ttbr1_cfg(adreno_smmu->cookie);
- if (!ttbr1_cfg)
+
+ /*
+ * If you hit this WARN_ONCE() you are probably missing an entry in
+ * qcom_smmu_impl_of_match[] in arm-smmu-qcom.c
+ */
+ if (WARN_ONCE(!ttbr1_cfg, "No per-process page tables"))
return ERR_PTR(-ENODEV);
/*
