[RFC PATCH v1 04/16] drm/nouveau: require reservations for nouveau_fence_sync and nouveau_bo_fence

Maarten Lankhorst
2014-05-14T14:57:51Z

This will ensure we always hold the required lock when calling those functions.
---
drivers/gpu/drm/nouveau/nouveau_bo.c | 2 ++
drivers/gpu/drm/nouveau/nouveau_display.c | 17 +++++++++++++----
2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index b6dc85c614be..33eb7164525a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1431,6 +1431,8 @@ nouveau_bo_fence(struct nouveau_bo *nvbo, struct nouveau_fence *fence)
struct nouveau_fence *new_fence = nouveau_fence_ref(fence);
struct nouveau_fence *old_fence = NULL;

+ lockdep_assert_held(&nvbo->bo.resv->lock.base);
+
spin_lock(&nvbo->bo.bdev->fence_lock);
old_fence = nvbo->bo.sync_obj;
nvbo->bo.sync_obj = new_fence;
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index da764a4ed958..61b8c3375135 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -716,6 +716,9 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
}

mutex_lock(&chan->cli->mutex);
+ ret = ttm_bo_reserve(&new_bo->bo, true, false, false, NULL);
+ if (ret)
+ goto fail_unpin;

/* synchronise rendering channel with the kernel's channel */
spin_lock(&new_bo->bo.bdev->fence_lock);
@@ -723,12 +726,18 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
spin_unlock(&new_bo->bo.bdev->fence_lock);
ret = nouveau_fence_sync(fence, chan);
nouveau_fence_unref(&fence);
- if (ret)
+ if (ret) {
+ ttm_bo_unreserve(&new_bo->bo);
goto fail_unpin;
+ }

- ret = ttm_bo_reserve(&old_bo->bo, true, false, false, NULL);
- if (ret)
- goto fail_unpin;
+ if (new_bo != old_bo) {
+ ttm_bo_unreserve(&new_bo->bo);
+
+ ret = ttm_bo_reserve(&old_bo->bo, true, false, false, NULL);
+ if (ret)
+ goto fail_unpin;
+ }

/* Initialize a page flip struct */
*s = (struct nouveau_page_flip_state)