[PATCH v3 1/3] drm/prime: use length macro when mapping sgl

[Shane Francis]

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

Signed-off-by: Shane Francis <bigbeeshane at gmail.com>
---
 drivers/gpu/drm/drm_prime.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 86d9b0e45c8c..e4eff5b84597 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -965,12 +965,14 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 	u32 len, index;
 	dma_addr_t addr;
 
+
 	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);
 
+
 		while (len > 0) {
 			if (WARN_ON(index >= max_entries))
 				return -1;
-- 
2.26.0