[PATCH] drm/msm/a6xx: don't set IO_PGTABLE_QUIRK_ARM_OUTER_WBWA with coherent SMMU

[Dmitry Baryshkov]

If the Adreno SMMU is dma-coherent, allocation will fail unless we
disable IO_PGTABLE_QUIRK_ARM_OUTER_WBWA. Skip setting this quirk for the
coherent SMMUs (like we have on sm8350 platform).

Fixes: 54af0ceb7595 ("arm64: dts: qcom: sm8350: add GPU, GMU, GPU CC and SMMU nodes")
Reported-by: David Heidelberg <david at ixit.cz>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 2942d2548ce6..f74495dcbd96 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1793,7 +1793,8 @@ a6xx_create_address_space(struct msm_gpu *gpu, struct platform_device *pdev)
 	 * This allows GPU to set the bus attributes required to use system
 	 * cache on behalf of the iommu page table walker.
 	 */
-	if (!IS_ERR_OR_NULL(a6xx_gpu->htw_llc_slice))
+	if (!IS_ERR_OR_NULL(a6xx_gpu->htw_llc_slice) &&
+	    !device_iommu_capable(&pdev->dev, IOMMU_CAP_CACHE_COHERENCY))
 		quirks |= IO_PGTABLE_QUIRK_ARM_OUTER_WBWA;
 
 	return adreno_iommu_create_address_space(gpu, pdev, quirks);
-- 
2.39.2