drm/msm: fix IOMMU cleanup for -EPROBE_DEFER

If probe fails after IOMMU is attached, we need to detach in order to
clean up properly.  Before this change, IOMMU faults would occur if the
probe failed (-EPROBE_DEFER).

Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index bb8026daebc9..690d7e7b6d1e 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -278,6 +278,7 @@ int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
                 uint32_t *iova)
 {
         struct msm_gem_object *msm_obj = to_msm_bo(obj);
+        struct drm_device *dev = obj->dev;
         int ret = 0;
 
         if (!msm_obj->domain[id].iova) {
@@ -285,6 +286,11 @@ int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
                 struct msm_mmu *mmu = priv->mmus[id];
                 struct page **pages = get_pages(obj);
 
+                if (!mmu) {
+                        dev_err(dev->dev, "null MMU pointer\n");
+                        return -EINVAL;
+                }
+
                 if (IS_ERR(pages))
                         return PTR_ERR(pages);