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drm/radeon/kms: IB locking dumps out a lockdep ordering issue 

We sometimes lock IB then the ring and sometimes the ring then
the IB. This is mostly due to the IB locking not being well defined
about what data in the structs it actually locks. Define what I
believe is the correct behaviour and gets rid of the lock dep ordering
warning.

Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Dave Airlie 2009-09-15 11:12:56 +10:00
parent 42dea5ddb5
commit ecb114a128
3 changed files with 22 additions and 8 deletions
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2
drivers/gpu/drm/radeon/r600_blit_kms.c
View File

@ -538,8 +538,8 @@ int r600_vb_ib_get(struct radeon_device *rdev)
void r600_vb_ib_put(struct radeon_device *rdev)
{
mutex_lock(&rdev->ib_pool.mutex);
radeon_fence_emit(rdev, rdev->r600_blit.vb_ib->fence);
mutex_lock(&rdev->ib_pool.mutex);
list_add_tail(&rdev->r600_blit.vb_ib->list, &rdev->ib_pool.scheduled_ibs);
mutex_unlock(&rdev->ib_pool.mutex);
radeon_ib_free(rdev, &rdev->r600_blit.vb_ib);

4
drivers/gpu/drm/radeon/radeon.h
View File

@ -402,6 +402,10 @@ struct radeon_ib {
uint32_t length_dw;
};
/*
* locking -
* mutex protects scheduled_ibs, ready, alloc_bm
*/
struct radeon_ib_pool {
struct mutex mutex;
struct radeon_object *robj;

24
drivers/gpu/drm/radeon/radeon_ring.c
View File

@ -56,10 +56,12 @@ int radeon_ib_get(struct radeon_device *rdev, struct radeon_ib **ib)
set_bit(i, rdev->ib_pool.alloc_bm);
rdev->ib_pool.ibs[i].length_dw = 0;
*ib = &rdev->ib_pool.ibs[i];
mutex_unlock(&rdev->ib_pool.mutex);
goto out;
}
if (list_empty(&rdev->ib_pool.scheduled_ibs)) {
/* we go do nothings here */
mutex_unlock(&rdev->ib_pool.mutex);
DRM_ERROR("all IB allocated none scheduled.\n");
r = -EINVAL;
goto out;
@ -69,10 +71,13 @@ int radeon_ib_get(struct radeon_device *rdev, struct radeon_ib **ib)
struct radeon_ib, list);
if (nib->fence == NULL) {
/* we go do nothings here */
mutex_unlock(&rdev->ib_pool.mutex);
DRM_ERROR("IB %lu scheduled without a fence.\n", nib->idx);
r = -EINVAL;
goto out;
}
mutex_unlock(&rdev->ib_pool.mutex);
r = radeon_fence_wait(nib->fence, false);
if (r) {
DRM_ERROR("radeon: IB(%lu:0x%016lX:%u)\n", nib->idx,
@ -81,12 +86,17 @@ int radeon_ib_get(struct radeon_device *rdev, struct radeon_ib **ib)
goto out;
}
radeon_fence_unref(&nib->fence);
nib->length_dw = 0;
/* scheduled list is accessed here */
mutex_lock(&rdev->ib_pool.mutex);
list_del(&nib->list);
INIT_LIST_HEAD(&nib->list);
mutex_unlock(&rdev->ib_pool.mutex);
*ib = nib;
out:
mutex_unlock(&rdev->ib_pool.mutex);
if (r) {
radeon_fence_unref(&fence);
} else {
@ -110,9 +120,10 @@ void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib **ib)
return;
}
list_del(&tmp->list);
if (tmp->fence) {
INIT_LIST_HEAD(&tmp->list);
if (tmp->fence)
radeon_fence_unref(&tmp->fence);
}
tmp->length_dw = 0;
clear_bit(tmp->idx, rdev->ib_pool.alloc_bm);
mutex_unlock(&rdev->ib_pool.mutex);
@ -122,25 +133,24 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
{
int r = 0;
mutex_lock(&rdev->ib_pool.mutex);
if (!ib->length_dw || !rdev->cp.ready) {
/* TODO: Nothings in the ib we should report. */
mutex_unlock(&rdev->ib_pool.mutex);
DRM_ERROR("radeon: couldn't schedule IB(%lu).\n", ib->idx);
return -EINVAL;
}
/* 64 dwords should be enough for fence too */
r = radeon_ring_lock(rdev, 64);
if (r) {
DRM_ERROR("radeon: scheduling IB failled (%d).\n", r);
mutex_unlock(&rdev->ib_pool.mutex);
return r;
}
radeon_ring_ib_execute(rdev, ib);
radeon_fence_emit(rdev, ib->fence);
radeon_ring_unlock_commit(rdev);
mutex_lock(&rdev->ib_pool.mutex);
list_add_tail(&ib->list, &rdev->ib_pool.scheduled_ibs);
mutex_unlock(&rdev->ib_pool.mutex);
radeon_ring_unlock_commit(rdev);
return 0;
}