[Mesa-dev] [PATCH 08/12] mesa: Fix incorrect access parameter passed to MapBuffer

[Keith Whitwell]

Your analysis sounds reasonable to me, Ian.  Looks good.

Keith

On Mon, 2011-08-22 at 00:33 -0700, Ian Romanick wrote:
> From: Ian Romanick <ian.d.romanick at intel.com>
> 
> The code previously passed GL_DYNAMIC_DRAW for the access parameter.
> By inspection, I believe that all drivers would treat this as
> GL_READ_WRITE because it's not GL_READ_ONLY and it's not
> GL_WRITE_ONLY.  However, my guess is that this code actually wants to
> use GL_WRITE_ONLY.
> 
> Cc: Eric Anholt <eric at anholt.net>
> Cc: Keith Whitwell <keithw at vmware.com>
> ---
>  src/mesa/drivers/dri/i965/brw_draw_upload.c |    4 +---
>  src/mesa/main/api_arrayelt.c                |    4 +---
>  2 files changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c
> index 66c42aa..3b95244 100644
> --- a/src/mesa/drivers/dri/i965/brw_draw_upload.c
> +++ b/src/mesa/drivers/dri/i965/brw_draw_upload.c
> @@ -689,9 +689,7 @@ static void brw_prepare_indices(struct brw_context *brw)
>         * rebase it into a temporary.
>         */
>         if ((get_size(index_buffer->type) - 1) & offset) {
> -           GLubyte *map = ctx->Driver.MapBuffer(ctx,
> -                                                GL_DYNAMIC_DRAW_ARB,
> -                                                bufferobj);
> +           GLubyte *map = ctx->Driver.MapBuffer(ctx, GL_READ_WRITE, bufferobj);
>             map += offset;
>  
>  	   intel_upload_data(&brw->intel, map, ib_size, ib_type_size,
> diff --git a/src/mesa/main/api_arrayelt.c b/src/mesa/main/api_arrayelt.c
> index 6400c8f..b897a33 100644
> --- a/src/mesa/main/api_arrayelt.c
> +++ b/src/mesa/main/api_arrayelt.c
> @@ -1602,9 +1602,7 @@ void _ae_map_vbos( struct gl_context *ctx )
>        _ae_update_state(ctx);
>  
>     for (i = 0; i < actx->nr_vbos; i++)
> -      ctx->Driver.MapBuffer(ctx,
> -			    GL_DYNAMIC_DRAW_ARB,
> -			    actx->vbo[i]);
> +      ctx->Driver.MapBuffer(ctx, GL_READ_WRITE, actx->vbo[i]);
>  
>     if (actx->nr_vbos)
>        actx->mapped_vbos = GL_TRUE;