[Mesa-dev] [PATCH] gallium/radeon: add a debug flag not to use write combining

[Michel Dänzer]

On 03.08.2015 21:36, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> ---
>  src/gallium/drivers/radeon/r600_buffer_common.c | 6 ++++--
>  src/gallium/drivers/radeon/r600_pipe_common.c   | 1 +
>  src/gallium/drivers/radeon/r600_pipe_common.h   | 1 +
>  3 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/src/gallium/drivers/radeon/r600_buffer_common.c b/src/gallium/drivers/radeon/r600_buffer_common.c
> index fc5f6c2..d5ee188 100644
> --- a/src/gallium/drivers/radeon/r600_buffer_common.c
> +++ b/src/gallium/drivers/radeon/r600_buffer_common.c
> @@ -111,7 +111,8 @@ bool r600_init_resource(struct r600_common_screen *rscreen,
>  
>  	switch (res->b.b.usage) {
>  	case PIPE_USAGE_STREAM:
> -		flags = RADEON_FLAG_GTT_WC;
> +		if (!(rscreen->debug_flags & DBG_NO_WC))
> +			flags = RADEON_FLAG_GTT_WC;
>  		/* fall through */
>  	case PIPE_USAGE_STAGING:
>  		/* Transfers are likely to occur more often with these resources. */
> @@ -133,7 +134,8 @@ bool r600_init_resource(struct r600_common_screen *rscreen,
>  	default:
>  		/* Not listing GTT here improves performance in some apps. */
>  		res->domains = RADEON_DOMAIN_VRAM;
> -		flags |= RADEON_FLAG_GTT_WC;
> +		if (!(rscreen->debug_flags & DBG_NO_WC))
> +			flags |= RADEON_FLAG_GTT_WC;
>  		break;
>  	}

I think it would be both simpler and safer to mask out
RADEON_FLAG_GTT_WC after all the code which sets the various flags.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer