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 --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); }