[Intel-gfx] [PATCH 4/6] drm/i915: Require fence only for FBC capable planes

[Chris Wilson]

Quoting Ville Syrjala (2018-02-21 16:02:33)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> As only a subset of primary planes are FBC capable there's no need
> to waste fences on all of them. So let's skip the fence if the plane
> isn't even fbc capable.
> 
> In the future we might extend this to skip the fence even for FBC
> capable planes if the crtc and/or plane state isn't suitable
> for FBC.
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 8aeb6b686bac..b4048b425ffd 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2076,7 +2076,7 @@ static bool intel_plane_uses_fence(const struct intel_plane_state *plane_state)
>         if (i915_gem_object_get_tiling(obj) == I915_TILING_NONE)
>                 return false;
>  
> -       return INTEL_GEN(dev_priv) < 4 || plane->id == PLANE_PRIMARY;
> +       return INTEL_GEN(dev_priv) < 4 || plane->has_fbc;

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris