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 78f520d05de92ea627980c5e8f2bb8388715e6fe..e3acc35e3805e58b09fa47fe8dc70223aff175dc 100644 (file)
--- 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;