[PATCH 59/74] drm/nv17-50: restore fence buffer on resume

[Herton Ronaldo Krzesinski]

3.5.7.4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcin Slusarz <marcin.slusarz at gmail.com>

commit f20ebd034eab43fd38c58b11c5bb5fb125e5f7d7 upstream.

Since commit 5e120f6e4b3f35b741c5445dfc755f50128c3c44 "drm/nouveau/fence:
convert to exec engine, and improve channel sync" nouveau fence sync
implementation for nv17-50 and nvc0+ started to rely on state of fence buffer
left by previous sync operation. But as pinned bo's (where fence state is
stored) are not saved+restored across suspend/resume, we need to do it
manually.

nvc0+ was fixed by commit d6ba6d215a538a58f0f0026f0961b0b9125e8042
"drm/nvc0/fence: restore pre-suspend fence buffer context on resume".

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=50121

Signed-off-by: Marcin Slusarz <marcin.slusarz at gmail.com>
Signed-off-by: Ben Skeggs <bskeggs at redhat.com>
[ herton: backport for 3.5, looks like we only need to call
  nouveau_bo_wr32 on nv10_fence_init ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/gpu/drm/nouveau/nv10_fence.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nv10_fence.c b/drivers/gpu/drm/nouveau/nv10_fence.c
index 8a1b750..18932a6 100644
--- a/drivers/gpu/drm/nouveau/nv10_fence.c
+++ b/drivers/gpu/drm/nouveau/nv10_fence.c
@@ -155,6 +155,9 @@ nv10_fence_fini(struct drm_device *dev, int engine, bool suspend)
 static int
 nv10_fence_init(struct drm_device *dev, int engine)
 {
+	struct nv10_fence_priv *priv = nv_engine(dev, engine);
+
+	nouveau_bo_wr32(priv->bo, 0, priv->sequence);
 	return 0;
 }
 
-- 
1.7.9.5