From 47f7826c520ecd92ffbffe59ecaa2fe61e42ec70 Mon Sep 17 00:00:00 2001 From: Shane Francis Date: Wed, 25 Mar 2020 09:07:41 +0000 Subject: [PATCH] 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: be62dbf554c5 ("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 Reviewed-by: Michael J. Ruhl Signed-off-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20200325090741.21957-4-bigbeeshane@gmail.com Cc: stable@vger.kernel.org --- drivers/gpu/drm/radeon/radeon_ttm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c index 3b92311..b3380ff 100644 --- a/drivers/gpu/drm/radeon/radeon_ttm.c +++ b/drivers/gpu/drm/radeon/radeon_ttm.c @@ -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, -- 2.7.4