[Intel-gfx] [PATCH 2/2] drm/i915: Add a test that we terminate the trimmed sgtable as expected

[Chris Wilson]

In commit 0c40ce130e38 ("drm/i915: Trim the object sg table"), we expect
to copy exactly orig_st->nents across and allocate the table thusly.
The copy loop should therefore end with the new_sg being NULL.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 4e263df2afc3..0a82cce5f731 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2316,6 +2316,7 @@ static void i915_sg_trim(struct sg_table *orig_st)
 		/* called before being DMA mapped, no need to copy sg->dma_* */
 		new_sg = sg_next(new_sg);
 	}
+	GEM_BUG_ON(new_sg); /* Should walk exactly nents and hit the end */
 
 	sg_free_table(orig_st);
 
-- 
2.11.0