Commit 42e67b47 authored Mar 25, 2020 by Shane Francis Committed by Alex Deucher Mar 25, 2020

drm/prime: use dma length macro when mapping sg

As dma_map_sg can reorganize scatter-gather lists in a
way that can cause some later segments to be empty we should
always use the sg_dma_len macro to fetch the actual length.

This could now be 0 and not need to be mapped to a page or
address array

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/20200325090741.21957-2-bigbeeshane@gmail.com
Cc: stable@vger.kernel.org

parent b216a8e7

drivers/gpu/drm/drm_prime.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -967,7 +967,7 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table sgt, struct page *pages,

		index = 0;
		for_each_sg(sgt->sgl, sg, sgt->nents, count) {
		len = sg->length;
		len = sg_dma_len(sg);
		page = sg_page(sg);
		addr = sg_dma_address(sg);

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