Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

3 files changed, 14 insertions, 6 deletions

diff --git a/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/dmanv04.c b/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/dmanv04.c
index bfcc6408a..b7f4b826f 100644
--- a/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/dmanv04.c
+++ b/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/dmanv04.c
@@ -36,7 +36,10 @@ nv04_fifo_dma_object_dtor(struct nvkm_fifo_chan *base, int cookie)
 {
 	struct nv04_fifo_chan *chan = nv04_fifo_chan(base);
 	struct nvkm_instmem *imem = chan->fifo->base.engine.subdev.device->imem;
+
+	mutex_lock(&chan->fifo->base.engine.subdev.mutex);
 	nvkm_ramht_remove(imem->ramht, cookie);
+	mutex_unlock(&chan->fifo->base.engine.subdev.mutex);
 }
 
 static int
diff --git a/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogf100.c b/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogf100.c
index e7cbc139c..89976ff4b 100644
--- a/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogf100.c
+++ b/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogf100.c
@@ -59,6 +59,7 @@ gf100_fifo_gpfifo_engine_fini(struct nvkm_fifo_chan *base,
 	struct nvkm_gpuobj *inst = chan->base.inst;
 	int ret = 0;
 
+	mutex_lock(&subdev->mutex);
 	nvkm_wr32(device, 0x002634, chan->base.chid);
 	if (nvkm_msec(device, 2000,
 		if (nvkm_rd32(device, 0x002634) == chan->base.chid)
@@ -66,10 +67,12 @@ gf100_fifo_gpfifo_engine_fini(struct nvkm_fifo_chan *base,
 	) < 0) {
 		nvkm_error(subdev, "channel %d [%s] kick timeout\n",
 			   chan->base.chid, chan->base.object.client->name);
-		ret = -EBUSY;
-		if (suspend)
-			return ret;
+		ret = -ETIMEDOUT;
 	}
+	mutex_unlock(&subdev->mutex);
+
+	if (ret && suspend)
+		return ret;
 
 	if (offset) {
 		nvkm_kmap(inst);
diff --git a/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogk104.c b/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogk104.c
index 0b817540a..aa1692e56 100644
--- a/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogk104.c
+++ b/kernel/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gpfifogk104.c
@@ -39,7 +39,9 @@ gk104_fifo_gpfifo_kick(struct gk104_fifo_chan *chan)
 	struct nvkm_subdev *subdev = &fifo->base.engine.subdev;
 	struct nvkm_device *device = subdev->device;
 	struct nvkm_client *client = chan->base.object.client;
+	int ret = 0;
 
+	mutex_lock(&subdev->mutex);
 	nvkm_wr32(device, 0x002634, chan->base.chid);
 	if (nvkm_msec(device, 2000,
 		if (!(nvkm_rd32(device, 0x002634) & 0x00100000))
@@ -47,10 +49,10 @@ gk104_fifo_gpfifo_kick(struct gk104_fifo_chan *chan)
 	) < 0) {
 		nvkm_error(subdev, "channel %d [%s] kick timeout\n",
 			   chan->base.chid, client->name);
-		return -EBUSY;
+		ret = -ETIMEDOUT;
 	}
-
-	return 0;
+	mutex_unlock(&subdev->mutex);
+	return ret;
 }
 
 static u32