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, 19 insertions, 1 deletions

diff --git a/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c b/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
index 59f735a93..e6a7d30c3 100644
--- a/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
+++ b/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
@@ -77,20 +77,36 @@ struct drm_gem_object *amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
 	list_add_tail(&bo->list, &adev->gem.objects);
 	mutex_unlock(&adev->gem.mutex);
 
+	bo->prime_shared_count = 1;
 	return &bo->gem_base;
 }
 
 int amdgpu_gem_prime_pin(struct drm_gem_object *obj)
 {
 	struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
-	int ret = 0;
+	long ret = 0;
 
 	ret = amdgpu_bo_reserve(bo, false);
 	if (unlikely(ret != 0))
 		return ret;
 
+	/*
+	 * Wait for all shared fences to complete before we switch to future
+	 * use of exclusive fence on this prime shared bo.
+	 */
+	ret = reservation_object_wait_timeout_rcu(bo->tbo.resv, true, false,
+						  MAX_SCHEDULE_TIMEOUT);
+	if (unlikely(ret < 0)) {
+		DRM_DEBUG_PRIME("Fence wait failed: %li\n", ret);
+		amdgpu_bo_unreserve(bo);
+		return ret;
+	}
+
 	/* pin buffer into GTT */
 	ret = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT, NULL);
+	if (likely(ret == 0))
+		bo->prime_shared_count++;
+
 	amdgpu_bo_unreserve(bo);
 	return ret;
 }
@@ -105,6 +121,8 @@ void amdgpu_gem_prime_unpin(struct drm_gem_object *obj)
 		return;
 
 	amdgpu_bo_unpin(bo);
+	if (bo->prime_shared_count)
+		bo->prime_shared_count--;
 	amdgpu_bo_unreserve(bo);
 }