[PATCH 3/5] drm/nouveau: require reservations for nouveau_fence_sync and nouveau_bo_fence

[Maarten Lankhorst]

This will ensure we always hold the required lock when calling those functions.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
---
 drivers/gpu/drm/nouveau/nouveau_bo.c      |  2 ++
 drivers/gpu/drm/nouveau/nouveau_display.c | 24 +++++++++++++++++-------
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c 
b/drivers/gpu/drm/nouveau/nouveau_bo.c
index c0fde6b9393c..38444ba22f0d 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1460,6 +1460,8 @@ 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 817b7c5c06f0..9d3892a1af96 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -609,19 +609,30 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct 
drm_framebuffer *fb,
                        goto fail_free;
        }

+       mutex_lock(&chan->cli->mutex);
+       ret = ttm_bo_reserve(&old_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);
        fence = nouveau_fence_ref(new_bo->bo.sync_obj);
        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;
+       }

-       mutex_lock(&chan->cli->mutex);
-       ret = ttm_bo_reserve(&old_bo->bo, true, false, false, NULL);
-       if (ret)
-               goto fail_unlock;
+       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)
@@ -673,9 +684,8 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct 
drm_framebuffer *fb,

 fail_unreserve:
        ttm_bo_unreserve(&old_bo->bo);
-fail_unlock:
-       mutex_unlock(&chan->cli->mutex);
 fail_unpin:
+       mutex_unlock(&chan->cli->mutex);
        if (old_bo != new_bo)
                nouveau_bo_unpin(new_bo);
 fail_free:
-- 
1.8.5.2