[PATCH] drm/radeon: hold reference to fences in radeon_sa_bo_new (3.17 and older) - dri-devel - freedesktop.org experimental mailing list

15 Mar 2016

From: Nicolai Hähnle nicolai.haehnle@amd.com
[Backport of upstream commit f6ff4f67cdf8455d0a4226eeeaf5af17c37d05eb, with
 an additional NULL pointer guard that is required for kernels 3.17 and older.
To be precise, any kernel that does *not* have commit 954605ca3 "drm/radeon:
 use common fence implementation for fences, v4" requires this additional
 NULL pointer guard.]
An arbitrary amount of time can pass between spin_unlock and
radeon_fence_wait_any, so we need to ensure that nobody frees the
fences from under us.
Based on the analogous fix for amdgpu.
Signed-off-by: Nicolai Hähnle nicolai.haehnle@amd.com
Reviewed-by: Christian König christian.koenig@amd.com (v1 + fix)
Tested-by: Lutz Euler lutz.euler@freenet.de
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/radeon/radeon_sa.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index c507896..7d11901 100644
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -349,8 +349,15 @@ 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) {
+			if (fences[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) {
-- 
2.5.0


    