Commit 47f7826c authored Mar 25, 2020 by Shane Francis Committed by Alex Deucher Mar 25, 2020

drm/radeon: fix scatter-gather mapping with user pages

Calls to dma_map_sg may return less segments / entries than requested
if they fall on page bounderies. The old implementation did not
support this use case.

Fixes: be62dbf5 ("iommu/amd: Convert AMD iommu driver to the dma-iommu api")
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=206461
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=206895
Bug: https://gitlab.freedesktop.org/drm/amd/issues/1056


Signed-off-by: Shane Francis <bigbeeshane@gmail.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200325090741.21957-4-bigbeeshane@gmail.com
Cc: stable@vger.kernel.org

parent 0199172f

drivers/gpu/drm/radeon/radeon_ttm.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -528,7 +528,7 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)

		r = -ENOMEM;
		nents = dma_map_sg(rdev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
		if (nents != ttm->sg->nents)
		if (nents == 0)
		goto release_sg;

		drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,

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