1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
index e07b95fe..c1f8a4f0 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
@@ -464,9 +464,17 @@ void gk20a_gmmu_free_attr(struct gk20a *g,
 
 static inline phys_addr_t gk20a_mem_phys(struct mem_desc *mem)
 {
-        /* the sgt may get null if this is accessed e.g. in an isr during
-         * channel deletion */
-        return mem->sgt ? sg_phys(mem->sgt->sgl) : 0;
+        /* FIXME: the sgt/sgl may get null if this is accessed e.g. in an isr
+         * during channel deletion - attempt to fix at least null derefs */
+        struct sg_table *sgt = mem->sgt;
+
+        if (sgt) {
+                struct scatterlist *sgl = sgt->sgl;
+                if (sgl)
+                        return sg_phys(sgl);
+        }
+
+        return 0;
 }
 
 u64 gk20a_locked_gmmu_map(struct vm_gk20a *vm,