[PATCH] drm/radeon: silence out possible lock dependency warning

[PATCH] drm/radeon: silence out possible lock dependency warning

[j.glisse]

From: Jerome Glisse <jglisse@redhat.com>

Silence out the lock dependency warning by moving bo allocation out
of ib mutex protected section. Might lead to useless temporary
allocation but it's not harmful as such things only happen at
initialization.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
---
 drivers/gpu/drm/radeon/radeon_ring.c |   19 +++++++++++--------
 1 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index e8bc709..1cb4b94 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -204,22 +204,25 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
 
 int radeon_ib_pool_init(struct radeon_device *rdev)
 {
+	struct radeon_sa_manager tmp;
 	int i, r;
 
-	mutex_lock(&rdev->ib_pool.mutex);
-	if (rdev->ib_pool.ready) {
-		mutex_unlock(&rdev->ib_pool.mutex);
-		return 0;
-	}
-
-	r = radeon_sa_bo_manager_init(rdev, &rdev->ib_pool.sa_manager,
+	r = radeon_sa_bo_manager_init(rdev, &tmp,
 				      RADEON_IB_POOL_SIZE*64*1024,
 				      RADEON_GEM_DOMAIN_GTT);
 	if (r) {
-		mutex_unlock(&rdev->ib_pool.mutex);
 		return r;
 	}
 
+	mutex_lock(&rdev->ib_pool.mutex);
+	if (rdev->ib_pool.ready) {
+		mutex_unlock(&rdev->ib_pool.mutex);
+		radeon_sa_bo_manager_fini(rdev, &tmp);
+		return 0;
+	}
+
+	rdev->ib_pool.sa_manager = tmp;
+	INIT_LIST_HEAD(&rdev->ib_pool.sa_manager.sa_bo);
 	for (i = 0; i < RADEON_IB_POOL_SIZE; i++) {
 		rdev->ib_pool.ibs[i].fence = NULL;
 		rdev->ib_pool.ibs[i].idx = i;
-- 
1.7.7.1

Re: [PATCH] drm/radeon: silence out possible lock dependency warning

[Alexandre Demers]

I suppose I can stop bisecting kernel about this possible lock and close
the bug then?

-- 
Alexandre Demers

Re: [PATCH] drm/radeon: silence out possible lock dependency warning

[Jerome Glisse]

On Tue, Jan 24, 2012 at 7:16 PM, Alexandre Demers
<alexandre.f.demers@gmail.com> wrote:
> I suppose I can stop bisecting kernel about this possible lock and close
> the bug then?
>
> --
> Alexandre Demers

Yes, unless the bug is something else as the error message could be
ignored and it wasn't
harmfull. ie even without that patch things couldn't go wrong.

Jerome