[PATCH 2/2] drm/amdgpu: fix scatter-gather mapping with user pages

[Shane Francis]

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

Signed-off-by: Shane Francis <bigbeeshane at gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index dee446278417..d07f143b50c3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -974,12 +974,13 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 	/* Map SG to device */
 	r = -ENOMEM;
 	nents = dma_map_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
-	if (nents != ttm->sg->nents)
+	if (nents == 0)
 		goto release_sg;
 
 	/* convert SG to linear array of pages and dma addresses */
-	drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
-					 gtt->ttm.dma_address, ttm->num_pages);
+	drm_prime_dma_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
+					gtt->ttm.dma_address, ttm->num_pages,
+					nents);
 
 	return 0;
 
-- 
2.26.0