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>

1 files changed, 23 insertions, 7 deletions

diff --git a/kernel/drivers/gpu/drm/i915/intel_ringbuffer.c b/kernel/drivers/gpu/drm/i915/intel_ringbuffer.c
index f6b2a814e..9d48443bc 100644
--- a/kernel/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/kernel/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1922,6 +1922,17 @@ i915_dispatch_execbuffer(struct drm_i915_gem_request *req,
 	return 0;
 }
 
+static void cleanup_phys_status_page(struct intel_engine_cs *ring)
+{
+	struct drm_i915_private *dev_priv = to_i915(ring->dev);
+
+	if (!dev_priv->status_page_dmah)
+		return;
+
+	drm_pci_free(ring->dev, dev_priv->status_page_dmah);
+	ring->status_page.page_addr = NULL;
+}
+
 static void cleanup_status_page(struct intel_engine_cs *ring)
 {
 	struct drm_i915_gem_object *obj;
@@ -1938,9 +1949,9 @@ static void cleanup_status_page(struct intel_engine_cs *ring)
 
 static int init_status_page(struct intel_engine_cs *ring)
 {
-	struct drm_i915_gem_object *obj;
+	struct drm_i915_gem_object *obj = ring->status_page.obj;
 
-	if ((obj = ring->status_page.obj) == NULL) {
+	if (obj == NULL) {
 		unsigned flags;
 		int ret;
 
@@ -2134,7 +2145,7 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 		if (ret)
 			goto error;
 	} else {
-		BUG_ON(ring->id != RCS);
+		WARN_ON(ring->id != RCS);
 		ret = init_phys_status_page(ring);
 		if (ret)
 			goto error;
@@ -2179,7 +2190,12 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring)
 	if (ring->cleanup)
 		ring->cleanup(ring);
 
-	cleanup_status_page(ring);
+	if (I915_NEED_GFX_HWS(ring->dev)) {
+		cleanup_status_page(ring);
+	} else {
+		WARN_ON(ring->id != RCS);
+		cleanup_phys_status_page(ring);
+	}
 
 	i915_cmd_parser_fini_ring(ring);
 	i915_gem_batch_pool_fini(&ring->batch_pool);
@@ -2341,11 +2357,11 @@ static int __intel_ring_prepare(struct intel_engine_cs *ring, int bytes)
 		if (unlikely(total_bytes > remain_usable)) {
 			/*
 			 * The base request will fit but the reserved space
-			 * falls off the end. So only need to to wait for the
-			 * reserved size after flushing out the remainder.
+			 * falls off the end. So don't need an immediate wrap
+			 * and only need to effectively wait for the reserved
+			 * size space from the start of ringbuffer.
 			 */
 			wait_bytes = remain_actual + ringbuf->reserved_size;
-			need_wrap = true;
 		} else if (total_bytes > ringbuf->space) {
 			/* No wrapping required, just waiting. */
 			wait_bytes = total_bytes;