[PATCH v3 4/5] drm/tegra: gem: Correct iommu_map_sg() error checking

From: Dmitry Osipenko
Date: Wed Dec 20 2017 - 10:51:05 EST


iommu_map_sg() doesn't return a error value, but a size of the requested
IOMMU mapping or zero in case of error.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
drivers/gpu/drm/tegra/gem.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index ab1e53d434e8..49b9bf28f872 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -114,7 +114,7 @@ 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 err;
+ int err;

if (bo->mm)
return -EBUSY;
@@ -128,22 +128,21 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
err = drm_mm_insert_node_generic(&tegra->mm,
bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
if (err < 0) {
- dev_err(tegra->drm->dev, "out of I/O virtual memory: %zd\n",
+ dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
err);
goto unlock;
}

bo->paddr = bo->mm->start;

- err = iommu_map_sg(tegra->domain, bo->paddr, bo->sgt->sgl,
- bo->sgt->nents, prot);
- if (err < 0) {
- dev_err(tegra->drm->dev, "failed to map buffer: %zd\n", err);
+ bo->size = iommu_map_sg(tegra->domain, bo->paddr, bo->sgt->sgl,
+ bo->sgt->nents, prot);
+ if (!bo->size) {
+ dev_err(tegra->drm->dev, "failed to map buffer\n");
+ err = -ENOMEM;
goto remove;
}

- bo->size = err;
-
mutex_unlock(&tegra->mm_lock);

return 0;
--
2.15.1