[PATCH 3/4] drm/msm: Fix iommu_map_sgtable() return value check and avoid WARN

[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.

Store the return value in the appropriate type and in case of error,
return it rather than WARNing.

Fixes: ad8f36e4b6b1 ("iommu: return full error code from iommu_map_sg[_atomic]()")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/gpu/drm/msm/msm_iommu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 7d449e5202c5..058c71c82cf5 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -677,7 +677,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
 			 int prot)
 {
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
-	size_t ret;
+	ssize_t ret;
 
 	WARN_ON(off != 0);
 
@@ -686,7 +686,8 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
 		iova |= GENMASK_ULL(63, 49);
 
 	ret = iommu_map_sgtable(iommu->domain, iova, sgt, prot);
-	WARN_ON(!ret);
+	if (ret < 0)
+		return ret;
 
 	return (ret == len) ? 0 : -EINVAL;
 }

-- 
2.53.0