[Mesa-dev] [PATCH 4/4] xa: reuse surfaces

[Thomas Hellstrom]

On 04/01/2014 05:04 PM, Rob Clark wrote:
> From: Rob Clark <robclark at freedesktop.org>
>
> Otherwise it will trick the gallium driver into thinking that the render
> target has actually changed (due to different pipe_surface pointing to
> same underlying pipe_resource).  This is really badness for tiling GPUs
> like adreno.

Rob, if we want to cache gallium surfaces like this, we need to
condition it on the same context being used.
We can't reuse a surface created with one context for rendering with
another context. (I know the mesa state tracker needs to
fix this up as well).

While this can be done easily within XA for non-shared xa_surfaces, I
wonder what happens in the case of
shared xa_surfaces? More specifically, is rendering allowed to be cached
in the gallium surface until explicitly flushed to the texture? (I'm
unsure about gallium surface semantics here).

/Thomas

> Signed-off-by: Rob Clark <robclark at freedesktop.org>
> ---
>  src/gallium/state_trackers/xa/xa_context.c | 35 +++++++++++++++++++++++-------
>  src/gallium/state_trackers/xa/xa_priv.h    |  3 ++-
>  src/gallium/state_trackers/xa/xa_tracker.c |  1 +
>  3 files changed, 30 insertions(+), 9 deletions(-)
>
> diff --git a/src/gallium/state_trackers/xa/xa_context.c b/src/gallium/state_trackers/xa/xa_context.c
> index 867999a..18f0b85 100644
> --- a/src/gallium/state_trackers/xa/xa_context.c
> +++ b/src/gallium/state_trackers/xa/xa_context.c
> @@ -179,6 +179,25 @@ xa_surface_unmap(struct xa_surface *srf)
>      }
>  }
>  
> +static int
> +xa_srf_create(struct xa_context *ctx, struct xa_surface *srf)
> +{
> +    struct pipe_screen *screen = ctx->pipe->screen;
> +    struct pipe_surface srf_templ;
> +
> +    if (!screen->is_format_supported(screen,  srf->tex->format,
> +				     PIPE_TEXTURE_2D, 0,
> +				     PIPE_BIND_RENDER_TARGET))
> +	return -XA_ERR_INVAL;
> +
> +    u_surface_default_template(&srf_templ, srf->tex);
> +    srf->srf = ctx->pipe->create_surface(ctx->pipe, srf->tex, &srf_templ);
> +    if (!srf->srf)
> +	return -XA_ERR_NORES;
> +
> +    return XA_ERR_NONE;
> +}
> +
>  int
>  xa_ctx_srf_create(struct xa_context *ctx, struct xa_surface *dst)
>  {
> @@ -188,15 +207,15 @@ xa_ctx_srf_create(struct xa_context *ctx, struct xa_surface *dst)
>      if (ctx->srf)
>  	return -XA_ERR_INVAL;
>  
> -    if (!screen->is_format_supported(screen,  dst->tex->format,
> -				     PIPE_TEXTURE_2D, 0,
> -				     PIPE_BIND_RENDER_TARGET))
> -	return -XA_ERR_INVAL;
> +    if (!dst->srf) {
> +	int ret = xa_srf_create(ctx, dst);
> +	if (ret != XA_ERR_NONE)
> +	    return ret;
> +    }
>  
> -    u_surface_default_template(&srf_templ, dst->tex);
> -    ctx->srf = ctx->pipe->create_surface(ctx->pipe, dst->tex, &srf_templ);
> -    if (!ctx->srf)
> -	return -XA_ERR_NORES;
> +    assert(dst->srf);
> +
> +    pipe_surface_reference(&ctx->srf, dst->srf);
>  
>      return XA_ERR_NONE;
>  }
> diff --git a/src/gallium/state_trackers/xa/xa_priv.h b/src/gallium/state_trackers/xa/xa_priv.h
> index 7a43386..5ade6c1 100644
> --- a/src/gallium/state_trackers/xa/xa_priv.h
> +++ b/src/gallium/state_trackers/xa/xa_priv.h
> @@ -46,7 +46,7 @@
>  #define XA_EXPORT
>  #endif
>  
> -#define XA_VB_SIZE (100 * 4 * 3 * 4)
> +#define XA_VB_SIZE (170 * 4 * 3 * 4)
>  #define XA_LAST_SURFACE_TYPE (xa_type_yuv_component + 1)
>  #define XA_MAX_SAMPLERS 3
>  
> @@ -65,6 +65,7 @@ struct xa_surface {
>      struct pipe_resource template;
>      struct xa_tracker *xa;
>      struct pipe_resource *tex;
> +    struct pipe_surface *srf;
>      struct pipe_transfer *transfer;
>      unsigned int flags;
>      struct xa_format_descriptor fdesc;
> diff --git a/src/gallium/state_trackers/xa/xa_tracker.c b/src/gallium/state_trackers/xa/xa_tracker.c
> index 9add584..7fed20a 100644
> --- a/src/gallium/state_trackers/xa/xa_tracker.c
> +++ b/src/gallium/state_trackers/xa/xa_tracker.c
> @@ -474,6 +474,7 @@ xa_surface_unref(struct xa_surface *srf)
>      if (srf == NULL || --srf->refcount) {
>  	return;
>      }
> +    pipe_surface_reference(&srf->srf, NULL);
>      pipe_resource_reference(&srf->tex, NULL);
>      free(srf);
>  }