Re: [PATCH 1/2] drm/radeon: Don't use WC for VRAM if !RADEON_GEM_GTT_WC

[Sergei Shtylyov <sergei.shtylyov@gmail.com>]

Hello!

On 09.09.2020 7:21, Huacai Chen wrote:

> Though RADEON_GEM_GTT_WC is initially used for GTT, but this flag is
> bound to drm_arch_can_wc_memory(), and if arch doesn't support WC, then
> VRAM should not use WC.
> 
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> ---
>   drivers/gpu/drm/radeon/radeon_object.c | 14 ++++++++++----
>   1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
> index f3dee01..07b82d9 100644
> --- a/drivers/gpu/drm/radeon/radeon_object.c
> +++ b/drivers/gpu/drm/radeon/radeon_object.c
> @@ -117,10 +117,16 @@ void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain)
>   						     TTM_PL_FLAG_VRAM;
>   		}
>   
> -		rbo->placements[c].fpfn = 0;
> -		rbo->placements[c++].flags = TTM_PL_FLAG_WC |
> -					     TTM_PL_FLAG_UNCACHED |
> -					     TTM_PL_FLAG_VRAM;
> +		if (rbo->flags & RADEON_GEM_GTT_WC) {
> +			rbo->placements[c].fpfn = 0;

    Shouldn't this statement be placed outside *if* as before?

> +			rbo->placements[c++].flags = TTM_PL_FLAG_WC |
> +						     TTM_PL_FLAG_UNCACHED |
> +						     TTM_PL_FLAG_VRAM;
> +		} else {
> +			rbo->placements[c].fpfn = 0;
> +			rbo->placements[c++].flags = TTM_PL_FLAG_UNCACHED |
> +						     TTM_PL_FLAG_VRAM;
> +		}
>   	}
>   
>   	if (domain & RADEON_GEM_DOMAIN_GTT) {

MBR, Sergei