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 at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at 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 --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);
}
--
1.7.4.1
