[3.11.y.z extended stable] Patch "drm/radeon: avoid segfault on device open when accel is not working." has been added to staging queue

[Luis Henriques]

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

    drm/radeon: avoid segfault on device open when accel is not working.

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

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

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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>From 3170f8e2b663a3190eb6b24e09edde2941be6858 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse at redhat.com>
Date: Wed, 7 May 2014 16:35:24 -0400
Subject: drm/radeon: avoid segfault on device open when accel is not working.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 24f47acc78b0ab5e2201f859fe1f693ae90c7c83 upstream.

When accel is not working on device with virtual address space radeon
segfault because the ib buffer is NULL and trying to map it inside the
virtual address space trigger segfault. This patch only map the ib
buffer if accel is working.

Signed-off-by: Jérôme Glisse <jglisse at redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/gpu/drm/radeon/radeon_kms.c | 57 +++++++++++++++++++------------------
 1 file changed, 30 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 82b87108457c..a6fb24a773e8 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -504,28 +504,29 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)

 		radeon_vm_init(rdev, &fpriv->vm);

-		r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false);
-		if (r) {
-			radeon_vm_fini(rdev, &fpriv->vm);
-			kfree(fpriv);
-			return r;
-		}
+		if (rdev->accel_working) {
+			r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false);
+			if (r) {
+				radeon_vm_fini(rdev, &fpriv->vm);
+				kfree(fpriv);
+				return r;
+			}

-		/* map the ib pool buffer read only into
-		 * virtual address space */
-		bo_va = radeon_vm_bo_add(rdev, &fpriv->vm,
-					 rdev->ring_tmp_bo.bo);
-		r = radeon_vm_bo_set_addr(rdev, bo_va, RADEON_VA_IB_OFFSET,
-					  RADEON_VM_PAGE_READABLE |
-					  RADEON_VM_PAGE_SNOOPED);
-
-		radeon_bo_unreserve(rdev->ring_tmp_bo.bo);
-		if (r) {
-			radeon_vm_fini(rdev, &fpriv->vm);
-			kfree(fpriv);
-			return r;
-		}
+			/* map the ib pool buffer read only into
+			 * virtual address space */
+			bo_va = radeon_vm_bo_add(rdev, &fpriv->vm,
+						 rdev->ring_tmp_bo.bo);
+			r = radeon_vm_bo_set_addr(rdev, bo_va, RADEON_VA_IB_OFFSET,
+						  RADEON_VM_PAGE_READABLE |
+						  RADEON_VM_PAGE_SNOOPED);

+			radeon_bo_unreserve(rdev->ring_tmp_bo.bo);
+			if (r) {
+				radeon_vm_fini(rdev, &fpriv->vm);
+				kfree(fpriv);
+				return r;
+			}
+		}
 		file_priv->driver_priv = fpriv;
 	}
 	return 0;
@@ -550,13 +551,15 @@ void radeon_driver_postclose_kms(struct drm_device *dev,
 		struct radeon_bo_va *bo_va;
 		int r;

-		r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false);
-		if (!r) {
-			bo_va = radeon_vm_bo_find(&fpriv->vm,
-						  rdev->ring_tmp_bo.bo);
-			if (bo_va)
-				radeon_vm_bo_rmv(rdev, bo_va);
-			radeon_bo_unreserve(rdev->ring_tmp_bo.bo);
+		if (rdev->accel_working) {
+			r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false);
+			if (!r) {
+				bo_va = radeon_vm_bo_find(&fpriv->vm,
+							  rdev->ring_tmp_bo.bo);
+				if (bo_va)
+					radeon_vm_bo_rmv(rdev, bo_va);
+				radeon_bo_unreserve(rdev->ring_tmp_bo.bo);
+			}
 		}

 		radeon_vm_fini(rdev, &fpriv->vm);
--
1.9.1