[PATCH 3/3] drm/i915: add some more checks for NULL bo->resource

[Matthew Auld]

It looks possible that we could see NULL bo->resource here. In practice
this should be treated as either swapped out or purged. In the case of
copy_ttm() the caller is meant to handle that, before calling into the
function. And in the case of ttm_backup, we don't need to backup such
objects.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 4 ++++
 drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c   | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
index 76dd9e5e1a8b..bcd89da570a6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
@@ -711,6 +711,10 @@ int i915_gem_obj_copy_ttm(struct drm_i915_gem_object *dst,
 
 	assert_object_held(dst);
 	assert_object_held(src);
+
+	if (!src_bo->resource || !dst_bo->resource)
+		return -EINVAL;
+
 	i915_deps_init(&deps, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
 
 	ret = dma_resv_reserve_fences(src_bo->base.resv, 1);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
index 09680e993b4b..9356d5b36d2f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
@@ -53,7 +53,7 @@ static int i915_ttm_backup(struct i915_gem_apply_to_region *apply,
 	unsigned int flags;
 	int err = 0;
 
-	if (bo->resource->mem_type == I915_PL_SYSTEM || obj->ttm.backup)
+	if (!bo->resource || bo->resource->mem_type == I915_PL_SYSTEM || obj->ttm.backup)
 		return 0;
 
 	if (pm_apply->allow_gpu && i915_gem_object_evictable(obj))
-- 
2.39.1