[Intel-gfx] [PATCH 15/28] drm/i915: Tidy handling of the scatterlist by ppgtt

[Chris Wilson]

Check to see if we've reached the end before dereferencing to get the
next scatterlist. This helps when creating scatterlists by hand.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 7afd631..fbdaf5a 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -194,13 +194,11 @@ static void i915_ppgtt_insert_sg_entries(struct i915_hw_ppgtt *ppgtt,
 			pt_vaddr[j] = pte | pte_flags;
 
 			/* grab the next page */
-			m++;
-			if (m == segment_len) {
-				sg = sg_next(sg);
-				i++;
-				if (i == sg_len)
+			if (++m == segment_len) {
+				if (++i == sg_len)
 					break;
 
+				sg = sg_next(sg);
 				segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
 				m = 0;
 			}
-- 
1.7.10