[PATCH 13/24] drm/radeon: fix a bug with the ring syncing code
j.glisse at gmail.com
j.glisse at gmail.com
Wed Apr 25 12:03:18 PDT 2012
From: Christian König <deathsimple at vodafone.de>
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 at vodafone.de>
---
drivers/gpu/drm/radeon/radeon.h | 4 ++
drivers/gpu/drm/radeon/radeon_cs.c | 35 ++++++------------
drivers/gpu/drm/radeon/radeon_semaphore.c | 56 +++++++++++++++++++++++++++++
drivers/gpu/drm/radeon/radeon_ttm.c | 48 +++++++++++--------------
4 files changed, 93 insertions(+), 50 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 575dc05..c7f14d7 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -442,6 +442,10 @@ void radeon_semaphore_emit_signal(struct radeon_device *rdev, int ring,
struct radeon_semaphore *semaphore);
void radeon_semaphore_emit_wait(struct radeon_device *rdev, int ring,
struct radeon_semaphore *semaphore);
+int radeon_semaphore_sync_rings(struct radeon_device *rdev,
+ struct radeon_semaphore *semaphore,
+ bool sync_to[RADEON_NUM_RINGS],
+ int dst_ring);
void radeon_semaphore_free(struct radeon_device *rdev,
struct radeon_semaphore *semaphore);
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 5cac832..64b86e7 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_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority
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 @@ static int radeon_cs_sync_rings(struct radeon_cs_parser *p)
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]);
+ if (!need_sync) {
+ return 0;
+ }
- 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]);
+ r = radeon_semaphore_create(p->rdev, &p->ib->fence->semaphore);
+ if (r) {
+ return r;
}
- return 0;
+
+ 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)
diff --git a/drivers/gpu/drm/radeon/radeon_semaphore.c b/drivers/gpu/drm/radeon/radeon_semaphore.c
index 9e2cf40..042dbfe 100644
--- a/drivers/gpu/drm/radeon/radeon_semaphore.c
+++ b/drivers/gpu/drm/radeon/radeon_semaphore.c
@@ -75,6 +75,62 @@ void radeon_semaphore_emit_wait(struct radeon_device *rdev, int ring,
radeon_semaphore_ring_emit(rdev, ring, &rdev->ring[ring], semaphore, true);
}
+int radeon_semaphore_sync_rings(struct radeon_device *rdev,
+ struct radeon_semaphore *semaphore,
+ bool sync_to[RADEON_NUM_RINGS],
+ int dst_ring)
+{
+ int i, r;
+
+ for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+ unsigned num_ops = i == dst_ring ? RADEON_NUM_RINGS : 1;
+
+ /* don't lock unused rings */
+ if (!sync_to[i] && i != dst_ring)
+ continue;
+
+ /* prevent GPU deadlocks */
+ if (!rdev->ring[i].ready) {
+ dev_err(rdev->dev, "Trying to sync to a disabled ring!");
+ r = -EINVAL;
+ goto error;
+ }
+
+ r = radeon_ring_lock(rdev, &rdev->ring[i], num_ops * 8);
+ if (r)
+ goto error;
+ }
+
+ for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+ /* no need to sync to our own or unused rings */
+ if (!sync_to[i] || i == dst_ring)
+ continue;
+
+ radeon_semaphore_emit_signal(rdev, i, semaphore);
+ radeon_semaphore_emit_wait(rdev, dst_ring, semaphore);
+ }
+
+ for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+
+ /* don't unlock unused rings */
+ if (!sync_to[i] && i != dst_ring)
+ continue;
+
+ radeon_ring_unlock_commit(rdev, &rdev->ring[i]);
+ }
+
+ return 0;
+
+error:
+ /* unlock all locks taken so far */
+ for (--i; i >= 0; --i) {
+ if (sync_to[i] || i == dst_ring) {
+ radeon_ring_unlock_undo(rdev, &rdev->ring[i]);
+ }
+ }
+ return r;
+}
+
void radeon_semaphore_free(struct radeon_device *rdev,
struct radeon_semaphore *semaphore)
{
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index f493c64..5e3d54d 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -222,8 +222,8 @@ static int radeon_move_blit(struct ttm_buffer_object *bo,
{
struct radeon_device *rdev;
uint64_t old_start, new_start;
- struct radeon_fence *fence;
- int r, i;
+ struct radeon_fence *fence, *old_fence;
+ int r;
rdev = radeon_get_rdev(bo->bdev);
r = radeon_fence_create(rdev, &fence, radeon_copy_ring_index(rdev));
@@ -242,6 +242,7 @@ static int radeon_move_blit(struct ttm_buffer_object *bo,
break;
default:
DRM_ERROR("Unknown placement %d\n", old_mem->mem_type);
+ radeon_fence_unref(&fence);
return -EINVAL;
}
switch (new_mem->mem_type) {
@@ -253,42 +254,35 @@ static int radeon_move_blit(struct ttm_buffer_object *bo,
break;
default:
DRM_ERROR("Unknown placement %d\n", old_mem->mem_type);
+ radeon_fence_unref(&fence);
return -EINVAL;
}
if (!rdev->ring[radeon_copy_ring_index(rdev)].ready) {
DRM_ERROR("Trying to move memory with ring turned off.\n");
+ radeon_fence_unref(&fence);
return -EINVAL;
}
BUILD_BUG_ON((PAGE_SIZE % RADEON_GPU_PAGE_SIZE) != 0);
/* sync other rings */
- if (rdev->family >= CHIP_R600) {
- for (i = 0; i < RADEON_NUM_RINGS; ++i) {
- /* no need to sync to our own or unused rings */
- if (i == radeon_copy_ring_index(rdev) || !rdev->ring[i].ready)
- continue;
-
- if (!fence->semaphore) {
- r = radeon_semaphore_create(rdev, &fence->semaphore);
- /* FIXME: handle semaphore error */
- if (r)
- continue;
- }
+ old_fence = bo->sync_obj;
+ if (old_fence && old_fence->ring != fence->ring
+ && !radeon_fence_signaled(old_fence)) {
+ bool sync_to_ring[RADEON_NUM_RINGS] = { };
+ sync_to_ring[old_fence->ring] = true;
+
+ r = radeon_semaphore_create(rdev, &fence->semaphore);
+ if (r) {
+ radeon_fence_unref(&fence);
+ return r;
+ }
- r = radeon_ring_lock(rdev, &rdev->ring[i], 3);
- /* FIXME: handle ring lock error */
- if (r)
- continue;
- radeon_semaphore_emit_signal(rdev, i, fence->semaphore);
- radeon_ring_unlock_commit(rdev, &rdev->ring[i]);
-
- r = radeon_ring_lock(rdev, &rdev->ring[radeon_copy_ring_index(rdev)], 3);
- /* FIXME: handle ring lock error */
- if (r)
- continue;
- radeon_semaphore_emit_wait(rdev, radeon_copy_ring_index(rdev), fence->semaphore);
- radeon_ring_unlock_commit(rdev, &rdev->ring[radeon_copy_ring_index(rdev)]);
+ r = radeon_semaphore_sync_rings(rdev, fence->semaphore,
+ sync_to_ring, fence->ring);
+ if (r) {
+ radeon_fence_unref(&fence);
+ return r;
}
}
--
1.7.7.6
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