drm/radeon: fix a bug with the ring syncing code
Rings need to lock in order, otherwise
the ring subsystem can deadlock.
v2: fix error handling and number of locked doublewords.
v3: stop creating unneeded semaphores.
Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index e7b0b5d..24fb0010 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -118,6 +118,7 @@
static int radeon_cs_sync_rings(struct radeon_cs_parser *p)
{
bool sync_to_ring[RADEON_NUM_RINGS] = { };
+ bool need_sync = false;
int i, r;
for (i = 0; i < p->nrelocs; i++) {
@@ -126,36 +127,24 @@
if (!(p->relocs[i].flags & RADEON_RELOC_DONT_SYNC)) {
struct radeon_fence *fence = p->relocs[i].robj->tbo.sync_obj;
- if (!radeon_fence_signaled(fence)) {
+ if (fence->ring != p->ring && !radeon_fence_signaled(fence)) {
sync_to_ring[fence->ring] = true;
+ need_sync = true;
}
}
}
- for (i = 0; i < RADEON_NUM_RINGS; ++i) {
- /* no need to sync to our own or unused rings */
- if (i == p->ring || !sync_to_ring[i] || !p->rdev->ring[i].ready)
- continue;
-
- if (!p->ib->fence->semaphore) {
- r = radeon_semaphore_create(p->rdev, &p->ib->fence->semaphore);
- if (r)
- return r;
- }
-
- r = radeon_ring_lock(p->rdev, &p->rdev->ring[i], 3);
- if (r)
- return r;
- radeon_semaphore_emit_signal(p->rdev, i, p->ib->fence->semaphore);
- radeon_ring_unlock_commit(p->rdev, &p->rdev->ring[i]);
-
- r = radeon_ring_lock(p->rdev, &p->rdev->ring[p->ring], 3);
- if (r)
- return r;
- radeon_semaphore_emit_wait(p->rdev, p->ring, p->ib->fence->semaphore);
- radeon_ring_unlock_commit(p->rdev, &p->rdev->ring[p->ring]);
+ if (!need_sync) {
+ return 0;
}
- return 0;
+
+ r = radeon_semaphore_create(p->rdev, &p->ib->fence->semaphore);
+ if (r) {
+ return r;
+ }
+
+ return radeon_semaphore_sync_rings(p->rdev, p->ib->fence->semaphore,
+ sync_to_ring, p->ring);
}
int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)