diff --git a/drivers/gpu/drm/etnaviv/etnaviv_dump.c b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
index 33854c94cb858f1cf62209e5f1c5e8d5de69e3e1..515515ef24f9adbad310199ca09c4478c1237d71 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_dump.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
@@ -125,6 +125,8 @@ void etnaviv_core_dump(struct etnaviv_gpu *gpu)
 		return;
 	etnaviv_dump_core = false;
 
+	mutex_lock(&gpu->mmu->lock);
+
 	mmu_size = etnaviv_iommu_dump_size(gpu->mmu);
 
 	/* We always dump registers, mmu, ring and end marker */
@@ -167,6 +169,7 @@ void etnaviv_core_dump(struct etnaviv_gpu *gpu)
 	iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
 			       PAGE_KERNEL);
 	if (!iter.start) {
+		mutex_unlock(&gpu->mmu->lock);
 		dev_warn(gpu->dev, "failed to allocate devcoredump file\n");
 		return;
 	}
@@ -234,6 +237,8 @@ void etnaviv_core_dump(struct etnaviv_gpu *gpu)
 					 obj->base.size);
 	}
 
+	mutex_unlock(&gpu->mmu->lock);
+
 	etnaviv_core_dump_header(&iter, ETDUMP_BUF_END, iter.data);
 
 	dev_coredumpv(gpu->dev, iter.start, iter.data - iter.start, GFP_KERNEL);