[PATCH 2/4] drm/tegra: Fix iommu_map_sgtable() return value check

[Mikko Perttunen <mperttunen@nvidia.com>]

Commit "iommu: return full error code from iommu_map_sg[_atomic]()"
changed iommu_map_sgtable() to return an ssize_t and negative values
in error cases, rather than a size_t and a zero.

Update tegra_bo_iommu_map() to correctly check for errors from
iommu_map_sgtable.

Fixes: ad8f36e4b6b1 ("iommu: return full error code from iommu_map_sg[_atomic]()")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/gpu/drm/tegra/gem.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index d2bae88ad545..684a16be2c0f 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -235,6 +235,7 @@ static const struct host1x_bo_ops tegra_bo_ops = {
 static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
 {
 	int prot = IOMMU_READ | IOMMU_WRITE;
+	ssize_t size;
 	int err;
 
 	if (bo->mm)
@@ -256,13 +257,15 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
 
 	bo->iova = bo->mm->start;
 
-	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
-	if (!bo->size) {
+	size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
+	if (size < 0) {
 		dev_err(tegra->drm->dev, "failed to map buffer\n");
-		err = -ENOMEM;
+		err = size;
 		goto remove;
 	}
 
+	bo->size = size;
+
 	mutex_unlock(&tegra->mm_lock);
 
 	return 0;

-- 
2.53.0