Patch "drm/amdgpu: fix lost sync_to if scheduler is enabled." has been added to the 4.4-stable tree

Patch "drm/amdgpu: fix lost sync_to if scheduler is enabled." has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/amdgpu: fix lost sync_to if scheduler is enabled.

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-amdgpu-fix-lost-sync_to-if-scheduler-is-enabled.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 888c9e33e4c5a503285921046c621f7c73199d2f Mon Sep 17 00:00:00 2001
From: Chunming Zhou <David1.Zhou@amd.com>
Date: Wed, 13 Jan 2016 12:55:18 +0800
Subject: drm/amdgpu: fix lost sync_to if scheduler is enabled.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Chunming Zhou <David1.Zhou@amd.com>

commit 888c9e33e4c5a503285921046c621f7c73199d2f upstream.

when scheduler is enabled, the semaphore isn't used at all.

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
@@ -293,7 +293,8 @@ int amdgpu_sync_rings(struct amdgpu_sync
 		fence = to_amdgpu_fence(sync->sync_to[i]);
 
 		/* check if we really need to sync */
-		if (!amdgpu_fence_need_sync(fence, ring))
+		if (!amdgpu_enable_scheduler &&
+		    !amdgpu_fence_need_sync(fence, ring))
 			continue;
 
 		/* prevent GPU deadlocks */
@@ -303,7 +304,7 @@ int amdgpu_sync_rings(struct amdgpu_sync
 		}
 
 		if (amdgpu_enable_scheduler || !amdgpu_enable_semaphores) {
-			r = fence_wait(&fence->base, true);
+			r = fence_wait(sync->sync_to[i], true);
 			if (r)
 				return r;
 			continue;


Patches currently in stable-queue which might be from David1.Zhou@amd.com are

queue-4.4/drm-amdgpu-fix-lost-sync_to-if-scheduler-is-enabled.patch