[Mesa-dev] [PATCH 2/4] gallium/radeon: don't discard DCC if an external user can write to it

[Nicolai Hähnle]

Patches 1 & 2:

Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>

On 03.06.2016 12:52, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
>
> We don't import textures with DCC now, but soon we will.
> ---
>   src/gallium/drivers/radeon/r600_pipe_common.h |  2 +-
>   src/gallium/drivers/radeon/r600_texture.c     | 31 +++++++++++++++++++--------
>   2 files changed, 23 insertions(+), 10 deletions(-)
>
> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
> index 8072833..2d60da4 100644
> --- a/src/gallium/drivers/radeon/r600_pipe_common.h
> +++ b/src/gallium/drivers/radeon/r600_pipe_common.h
> @@ -676,7 +676,7 @@ void evergreen_do_fast_color_clear(struct r600_common_context *rctx,
>   				   struct r600_atom *fb_state,
>   				   unsigned *buffers, unsigned *dirty_cbufs,
>   				   const union pipe_color_union *color);
> -void r600_texture_disable_dcc(struct r600_common_screen *rscreen,
> +bool r600_texture_disable_dcc(struct r600_common_screen *rscreen,
>   			      struct r600_texture *rtex);
>   void r600_init_screen_texture_functions(struct r600_common_screen *rscreen);
>   void r600_init_context_texture_functions(struct r600_common_context *rctx);
> diff --git a/src/gallium/drivers/radeon/r600_texture.c b/src/gallium/drivers/radeon/r600_texture.c
> index 71758c4..0f5c08f 100644
> --- a/src/gallium/drivers/radeon/r600_texture.c
> +++ b/src/gallium/drivers/radeon/r600_texture.c
> @@ -32,7 +32,7 @@
>   #include <errno.h>
>   #include <inttypes.h>
>
> -static void r600_texture_discard_dcc(struct r600_common_screen *rscreen,
> +static bool r600_texture_discard_dcc(struct r600_common_screen *rscreen,
>   				     struct r600_texture *rtex);
>   static void r600_texture_discard_cmask(struct r600_common_screen *rscreen,
>   				       struct r600_texture *rtex);
> @@ -86,7 +86,8 @@ bool r600_prepare_for_dma_blit(struct r600_common_context *rctx,
>   						      src_box->height, src_box->depth))
>   			return false;
>
> -		r600_texture_discard_dcc(rctx->screen, rdst);
> +		if (!r600_texture_discard_dcc(rctx->screen, rdst))
> +			return false;
>   	}
>
>   	/* CMASK as:
> @@ -376,25 +377,37 @@ static void r600_texture_discard_cmask(struct r600_common_screen *rscreen,
>   	p_atomic_inc(&rscreen->compressed_colortex_counter);
>   }
>
> -static void r600_texture_discard_dcc(struct r600_common_screen *rscreen,
> +static bool r600_can_disable_dcc(struct r600_texture *rtex)
> +{
> +	/* We can't disable DCC if it can be written by another process. */
> +	return rtex->dcc_offset &&
> +	       (!rtex->resource.is_shared ||
> +		!(rtex->resource.external_usage & PIPE_HANDLE_USAGE_WRITE));
> +}
> +
> +static bool r600_texture_discard_dcc(struct r600_common_screen *rscreen,
>   				     struct r600_texture *rtex)
>   {
> +	if (!r600_can_disable_dcc(rtex))
> +		return false;
> +
>   	/* Disable DCC. */
>   	rtex->dcc_offset = 0;
>   	rtex->cb_color_info &= ~VI_S_028C70_DCC_ENABLE(1);
>
>   	/* Notify all contexts about the change. */
>   	r600_dirty_all_framebuffer_states(rscreen);
> +	return true;
>   }
>
> -void r600_texture_disable_dcc(struct r600_common_screen *rscreen,
> +bool r600_texture_disable_dcc(struct r600_common_screen *rscreen,
>   			      struct r600_texture *rtex)
>   {
>   	struct r600_common_context *rctx =
>   		(struct r600_common_context *)rscreen->aux_context;
>
> -	if (!rtex->dcc_offset)
> -		return;
> +	if (!r600_can_disable_dcc(rtex))
> +		return false;
>
>   	/* Decompress DCC. */
>   	pipe_mutex_lock(rscreen->aux_context_lock);
> @@ -402,7 +415,7 @@ void r600_texture_disable_dcc(struct r600_common_screen *rscreen,
>   	rctx->b.flush(&rctx->b, NULL, 0);
>   	pipe_mutex_unlock(rscreen->aux_context_lock);
>
> -	r600_texture_discard_dcc(rscreen, rtex);
> +	return r600_texture_discard_dcc(rscreen, rtex);
>   }
>
>   static void r600_degrade_tile_mode_to_linear(struct r600_common_context *rctx,
> @@ -497,8 +510,8 @@ static boolean r600_texture_get_handle(struct pipe_screen* screen,
>   		 * access.
>   		 */
>   		if (usage & PIPE_HANDLE_USAGE_WRITE && rtex->dcc_offset) {
> -			r600_texture_disable_dcc(rscreen, rtex);
> -			update_metadata = true;
> +			if (r600_texture_disable_dcc(rscreen, rtex))
> +				update_metadata = true;
>   		}
>
>   		if (!(usage & PIPE_HANDLE_USAGE_EXPLICIT_FLUSH) &&
>