[Intel-gfx] [PATCH 04/14] Revert "drm/i915/sprite: Always enable the scaler on IronLake"

[Imre Deak]

On Thu, 2013-12-05 at 15:51 +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Apparently always enabling the sprite scaler magically made
> sprites work on ILK in the past.
> 
> I think the real reason for the failure was missing sprite
> watermark programming, and enabling the scaler effectively
> disabled LP1+ watermarks, which was enough to keep things going.
> Or it might be that the hardware more or less ignores watermarks
> for scaled sprites since things seem to work even if I leave
> sprite watermarks at 0 and disable all other planes except the
> sprite.
> 
> In any case, we left the scaler always on but then failed to
> check whether we might be exceeding the scaler's source size
> limits. That caused the sprite to fail when a sufficiently
> large unscaled image was being displayed.
> 
> Now that we're getting proper watermark programming for ILK, we
> can keep the scaler disabled unless we need to do actual scaling.
> 
> This reverts commit 8aaa81a166d80ac9bf2813984e5b4c2503d0fe08.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Since we switch to the new calculation only at patch 11/14, it'd be
better to apply this after that, so we don't re-introduce the issue in
between.

--Imre

> ---
>  drivers/gpu/drm/i915/intel_sprite.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
> index 90a3f6d..6bfebfb 100644
> --- a/drivers/gpu/drm/i915/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/intel_sprite.c
> @@ -488,7 +488,7 @@ ilk_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
>  	crtc_h--;
>  
>  	dvsscale = 0;
> -	if (IS_GEN5(dev) || crtc_w != src_w || crtc_h != src_h)
> +	if (crtc_w != src_w || crtc_h != src_h)
>  		dvsscale = DVS_SCALE_ENABLE | (src_w << 16) | src_h;
>  
>  	I915_WRITE(DVSSTRIDE(pipe), fb->pitches[0]);