Merge tag 'topic/drm-misc-2016-08-23' of git://anongit.freedesktop.org/drm-intel into drm-next

A few bigger things:
- start of splitting drm_crtc.c into more manageable and better documneted
  chunks
- DRM_DEV_* logging (Sean)

* tag 'topic/drm-misc-2016-08-23' of git://anongit.freedesktop.org/drm-intel: (46 commits)
  drm/fb-helper: Make docs for fb_set_suspend wrappers consistent
  drm/rockchip: Delete unnecessary assignment for the field "owner"
  drm/bridge: dw-hdmi: Delete unnecessary assignment for the field "owner"
  drm/rockchip: Don't continue trying to enable crtc on failure
  drm/fb-helper: Add drm_fb_helper_set_suspend_unlocked()
  drm/fb-helper: Fix the dummy remove_conflicting_framebuffers
  drm/udl: Ensure channel is selected before using the device.
  drm: Avoid calling dev_printk(.dev = NULL)
  drm: avoid exposing kernel stack in compat_drm_getstats
  reservation: fix small comment typo
  drm: Don't implement empty prepare_fb()/cleanup_fb()
  virtio-gpu: Use memdup_user() rather than duplicating its implementation
  GPU-DRM-Savage: Use memdup_user() rather than duplicating
  drm: Allow drivers to modify plane_state in prepare_fb/cleanup_fb
  drm/rockchip: Use DRM_DEV_ERROR in vop
  drm: Introduce DRM_DEV_* log messages
  drm/edid: CEA mode 64 1080p100 vsync pulse width incorrect
  Revert "drm/hisilicon: Don't set drm_device->platformdev"
  dma-buf: fix kernel-doc warning and typos
  drm: Fix kerneldoc in drm_plane_helper.c
  ...

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index ddaee60ae52a..cf04d249a6a4 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -586,6 +586,22 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 }
 EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
 
+static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+				      enum dma_data_direction direction)
+{
+	bool write = (direction == DMA_BIDIRECTIONAL ||
+		      direction == DMA_TO_DEVICE);
+	struct reservation_object *resv = dmabuf->resv;
+	long ret;
+
+	/* Wait on any implicit rendering fences */
+	ret = reservation_object_wait_timeout_rcu(resv, write, true,
+						  MAX_SCHEDULE_TIMEOUT);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
 
 /**
  * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
@@ -608,6 +624,13 @@ int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
 	if (dmabuf->ops->begin_cpu_access)
 		ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
 
+	/* Ensure that all fences are waited upon - but we first allow
+	 * the native handler the chance to do so more efficiently if it
+	 * chooses. A double invocation here will be reasonably cheap no-op.
+	 */
+	if (ret == 0)
+		ret = __dma_buf_begin_cpu_access(dmabuf, direction);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);