diff mbox

[06/10] drm/exynos: add wait_for_vblank callback interface.

Message ID 1345466155-9154-7-git-send-email-inki.dae@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Inki Dae Aug. 20, 2012, 12:35 p.m. UTC 
this interface can be used to make sure that hardware overlay is disabled
to avoid that memory region is accessed by dma after gem buffer was released.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_drv.h     |   17 +++++++++++++++++
 drivers/gpu/drm/exynos/exynos_drm_encoder.c |   10 ++++++++++
 2 files changed, 27 insertions(+), 0 deletions(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index 24c45d8..00e4bdc 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -37,6 +37,20 @@ 
 #define MAX_FB_BUFFER	4
 #define DEFAULT_ZPOS	-1
 
+#define _wait_for(COND, MS) ({ \
+	unsigned long timeout__ = jiffies + msecs_to_jiffies(MS);	\
+	int ret__ = 0;							\
+	while (!(COND)) {						\
+		if (time_after(jiffies, timeout__)) {			\
+			ret__ = -ETIMEDOUT;				\
+			break;						\
+		}							\
+	}								\
+	ret__;								\
+})
+
+#define wait_for(COND, MS) _wait_for(COND, MS)
+
 struct drm_device;
 struct exynos_drm_overlay;
 struct drm_connector;
@@ -61,6 +75,8 @@  enum exynos_drm_output_type {
  * @commit: apply hardware specific overlay data to registers.
  * @enable: enable hardware specific overlay.
  * @disable: disable hardware specific overlay.
+ * @wait_for_vblank: wait for vblank interrupt to make sure that
+ *	dma transfer is completed.
  */
 struct exynos_drm_overlay_ops {
 	void (*mode_set)(struct device *subdrv_dev,
@@ -68,6 +84,7 @@  struct exynos_drm_overlay_ops {
 	void (*commit)(struct device *subdrv_dev, int zpos);
 	void (*enable)(struct device *subdrv_dev, int zpos);
 	void (*disable)(struct device *subdrv_dev, int zpos);
+	void (*wait_for_vblank)(struct device *subdrv_dev);
 };
 
 /*
diff --git a/drivers/gpu/drm/exynos/exynos_drm_encoder.c b/drivers/gpu/drm/exynos/exynos_drm_encoder.c
index 08ba62f..98d5576 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_encoder.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_encoder.c
@@ -430,4 +430,14 @@  void exynos_drm_encoder_plane_disable(struct drm_encoder *encoder, void *data)
 
 	if (overlay_ops && overlay_ops->disable)
 		overlay_ops->disable(manager->dev, zpos);
+
+	/*
+	 * wait for vblank interrupt
+	 * - with iommu, the dma operation could induce page fault
+	 * when accessed to memory after gem buffer was released so
+	 * make sure that the dma operation is completed before releasing
+	 * the gem bufer.
+	 */
+	if (overlay_ops->wait_for_vblank)
+		overlay_ops->wait_for_vblank(manager->dev);
 }