From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Date: Mon, 15 Feb 2016 18:41:46 +0000 (+0100)
Subject: drm/nouveau: use post-decrement in error handling
X-Git-Tag: v4.14-rc1~3797^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4fbbed46dca83bcba3a0170205110a06c116a8e6;p=platform%2Fkernel%2Flinux-rpi.git

drm/nouveau: use post-decrement in error handling

We need to use post-decrement to get the dma_map_page undone also for
i==0, and to avoid some very unpleasant behaviour if dma_map_page
failed already at i==0.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 78f520d..e3acc35 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1520,7 +1520,7 @@ nouveau_ttm_tt_populate(struct ttm_tt *ttm)
 				    DMA_BIDIRECTIONAL);
 
 		if (dma_mapping_error(pdev, addr)) {
-			while (--i) {
+			while (i--) {
 				dma_unmap_page(pdev, ttm_dma->dma_address[i],
 					       PAGE_SIZE, DMA_BIDIRECTIONAL);
 				ttm_dma->dma_address[i] = 0;