[3.16.y-ckt stable] Patch "Revert "drm/radeon: hold reference to fences in radeon_sa_bo_new"" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Revert "drm/radeon: hold reference to fences in radeon_sa_bo_new"

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt26.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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>From 570300978c079a3f64b9957291d119cca865480a Mon Sep 17 00:00:00 2001
From: Luis Henriques <luis.henriques at canonical.com>
Date: Wed, 9 Mar 2016 13:58:27 +0000
Subject: Revert "drm/radeon: hold reference to fences in radeon_sa_bo_new"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This reverts commit 73187980dfefe5198aadcfdf0a377e461eed2bfa, which was
commit f6ff4f67cdf8455d0a4226eeeaf5af17c37d05eb upstream.

This patch was triggering a Oops in stable kernel 3.10.99.  Christian
agrees that the patch is correct but "assumes that radeon_fence_unref()
can safely take NULL as the fence which is not the case for older
kernels."

Reported-by: Erik Andersen <andersen at codepoet.org>
Acked-by: Christian König <christian.koenig at amd.com>
Cc: Nicolai Hähnle <nicolai.haehnle at amd.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/gpu/drm/radeon/radeon_sa.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index 15fd57296081..adcf3e2f07da 100644
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -349,13 +349,8 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
 			/* see if we can skip over some allocations */
 		} while (radeon_sa_bo_next_hole(sa_manager, fences, tries));

-		for (i = 0; i < RADEON_NUM_RINGS; ++i)
-			radeon_fence_ref(fences[i]);
-
 		spin_unlock(&sa_manager->wq.lock);
 		r = radeon_fence_wait_any(rdev, fences, false);
-		for (i = 0; i < RADEON_NUM_RINGS; ++i)
-			radeon_fence_unref(&fences[i]);
 		spin_lock(&sa_manager->wq.lock);
 		/* if we have nothing to wait for block */
 		if (r == -ENOENT) {