[PATCH] drm/nouveau: unpin pushbuffer bo before destroying it

[Marcin Slusarz <marcin.slusarz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Fixes GART leak (as accounted by nouveau_drm.gem.gart_available).

Signed-off-by: Marcin Slusarz <marcin.slusarz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---

Running glxinfo in a loop is enough to trigger it - after several thousand
runs (depending on GART size), X server crashes and does not come back in
a correct state (corruptions and crashes).

With this patch applied, it's possible again to do full piglit run (with
concurrency disabled) without crashes or lockups.

---
 drivers/gpu/drm/nouveau/nouveau_chan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_chan.c b/drivers/gpu/drm/nouveau/nouveau_chan.c
index 1363578..174300b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_chan.c
+++ b/drivers/gpu/drm/nouveau/nouveau_chan.c
@@ -76,6 +76,8 @@ nouveau_channel_del(struct nouveau_channel **pchan)
 		nouveau_object_del(client, NVDRM_DEVICE, chan->push.handle);
 		nouveau_bo_vma_del(chan->push.buffer, &chan->push.vma);
 		nouveau_bo_unmap(chan->push.buffer);
+		if (chan->push.buffer && chan->push.buffer->pin_refcnt)
+			nouveau_bo_unpin(chan->push.buffer);
 		nouveau_bo_ref(NULL, &chan->push.buffer);
 		kfree(chan);
 	}
-- 
1.7.12