[PATCH] Revert "drm/nouveau/fifo/gk104: kick channels when deactivating them"

[Alexandre Courbot <acourbot@nvidia.com>]

This reverts commit 1addc1264852

This commit seems to cause crashes in gk104_fifo_intr_runlist() by
returning 0xbad0da00 when register 0x2a00 is read. Since this commit was
intended for GM20B which is not completely supported yet, let's revert
it for the time being.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
David, it would be great if this could be merged for 4.2 since lots of
users could potentially experience this issue. Thanks!

 drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c | 29 +++++++-----------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
index 52c22b026005..e10f9644140f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
@@ -166,30 +166,14 @@ gk104_fifo_context_attach(struct nvkm_object *parent,
 }
 
 static int
-gk104_fifo_chan_kick(struct gk104_fifo_chan *chan)
-{
-	struct nvkm_object *obj = (void *)chan;
-	struct gk104_fifo_priv *priv = (void *)obj->engine;
-
-	nv_wr32(priv, 0x002634, chan->base.chid);
-	if (!nv_wait(priv, 0x002634, 0x100000, 0x000000)) {
-		nv_error(priv, "channel %d [%s] kick timeout\n",
-			 chan->base.chid, nvkm_client_name(chan));
-		return -EBUSY;
-	}
-
-	return 0;
-}
-
-static int
 gk104_fifo_context_detach(struct nvkm_object *parent, bool suspend,
 			  struct nvkm_object *object)
 {
 	struct nvkm_bar *bar = nvkm_bar(parent);
+	struct gk104_fifo_priv *priv = (void *)parent->engine;
 	struct gk104_fifo_base *base = (void *)parent->parent;
 	struct gk104_fifo_chan *chan = (void *)parent;
 	u32 addr;
-	int ret;
 
 	switch (nv_engidx(object->engine)) {
 	case NVDEV_ENGINE_SW    : return 0;
@@ -204,9 +188,13 @@ gk104_fifo_context_detach(struct nvkm_object *parent, bool suspend,
 		return -EINVAL;
 	}
 
-	ret = gk104_fifo_chan_kick(chan);
-	if (ret && suspend)
-		return ret;
+	nv_wr32(priv, 0x002634, chan->base.chid);
+	if (!nv_wait(priv, 0x002634, 0xffffffff, chan->base.chid)) {
+		nv_error(priv, "channel %d [%s] kick timeout\n",
+			 chan->base.chid, nvkm_client_name(chan));
+		if (suspend)
+			return -EBUSY;
+	}
 
 	if (addr) {
 		nv_wo32(base, addr + 0x00, 0x00000000);
@@ -331,7 +319,6 @@ gk104_fifo_chan_fini(struct nvkm_object *object, bool suspend)
 		gk104_fifo_runlist_update(priv, chan->engine);
 	}
 
-	gk104_fifo_chan_kick(chan);
 	nv_wr32(priv, 0x800000 + (chid * 8), 0x00000000);
 	return nvkm_fifo_channel_fini(&chan->base, suspend);
 }
-- 
2.5.0