Re: [PATCH 08/13] drm/exynos: make sure that hardware overlay for fimd is disabled

[Joonyoung Shim <jy0922.shim@samsung.com>]

On 08/17/2012 06:50 PM, Inki Dae wrote:
> the values set to registers will be updated into real registers
> at vsync so dma operation could be malfunctioned when accessed
> to memory after gem buffer was released. this patch makes sure
> that hw overlay is disabled before the gem buffer is 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 ++++++++++
>   drivers/gpu/drm/exynos/exynos_drm_fimd.c    |   12 ++++++++++++

Please split patch to exynos_drm part and fimd part.

>   3 files changed, 39 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 7da5714..a562a94 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_encoder.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_encoder.c
> @@ -399,4 +399,14 @@ 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);
>   }
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> index 0ec9d86..2378d80 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> @@ -570,10 +570,22 @@ static void fimd_win_disable(struct device *dev, int zpos)
>   	win_data->enabled = false;
>   }
>   
> +static void fimd_wait_for_vblank(struct device *dev)
> +{
> +	struct fimd_context *ctx = get_fimd_context(dev);
> +	int ret;
> +
> +	ret = wait_for((__raw_readl(ctx->regs + VIDCON1) &
> +					VIDCON1_VSTATUS_BACKPORCH), 50);
> +	if (ret < 0)
> +		DRM_DEBUG_KMS("vblank wait timed out.\n");
> +}
> +
>   static struct exynos_drm_overlay_ops fimd_overlay_ops = {
>   	.mode_set = fimd_win_mode_set,
>   	.commit = fimd_win_commit,
>   	.disable = fimd_win_disable,
> +	.wait_for_vblank = fimd_wait_for_vblank,
>   };
>   
>   static struct exynos_drm_manager fimd_manager = {