drm/nouveau/disp/nv50-: fix push buffers in vram

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c
index 84ade81..8ba808d 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c
@@ -229,7 +229,7 @@
 
 		switch (dmac->pushdma->target) {
 		case NV_MEM_TARGET_VRAM:
-			dmac->push = 0x00000000 | dmac->pushdma->start >> 8;
+			dmac->push = 0x00000001 | dmac->pushdma->start >> 8;
 			break;
 		case NV_MEM_TARGET_PCI_NOSNOOP:
 			dmac->push = 0x00000003 | dmac->pushdma->start >> 8;