Re: [PATCH 9/9] drm/i915: fix FBC for cases where crtc->base.y is non-zero

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Sep 14, 2015 at 03:20:03PM -0300, Paulo Zanoni wrote:
> I only tested this on BDW and SKL, but since the register description
> is the same ever since gen4, let's assume that all gens take the same
> register format. If that's not true, then hopefully someone will
> bisect a bug to this patch and we'll fix it.
> 
> Notice that the wrong fence offset register just means that the
> hardware tracking will be wrong.
> 
> Testcases:
>  - igt/kms_frontbuffer_tracking/fbc-1p-primscrn-pri-shrfb-draw-mmap-gtt
>  - igt/kms_frontbuffer_tracking/fbc-2p-primscrn-pri-shrfb-draw-mmap-gtt
> 
> v2:
>   - Add intel_crtc->adjusted_{x,y} so this code can work independently
>     of intel_gen4_compute_page_offset(). (Ville).
>   - This version also works on SKL.
> 
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c |  9 +++++++++
>  drivers/gpu/drm/i915/intel_drv.h     |  2 ++
>  drivers/gpu/drm/i915/intel_fbc.c     | 25 ++++++++++++++++++++-----
>  3 files changed, 31 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index fc00867..c27a636 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2730,6 +2730,9 @@ static void i9xx_update_primary_plane(struct drm_crtc *crtc,
>  			(intel_crtc->config->pipe_src_w - 1) * pixel_size;
>  	}
>  
> +	intel_crtc->adjusted_x = x;
> +	intel_crtc->adjusted_y = y;
> +
>  	I915_WRITE(reg, dspcntr);
>  
>  	I915_WRITE(DSPSTRIDE(plane), fb->pitches[0]);
> @@ -2830,6 +2833,9 @@ static void ironlake_update_primary_plane(struct drm_crtc *crtc,
>  		}
>  	}
>  
> +	intel_crtc->adjusted_x = x;
> +	intel_crtc->adjusted_y = y;
> +
>  	I915_WRITE(reg, dspcntr);
>  
>  	I915_WRITE(DSPSTRIDE(plane), fb->pitches[0]);
> @@ -3082,6 +3088,9 @@ static void skylake_update_primary_plane(struct drm_crtc *crtc,
>  	}
>  	plane_offset = y_offset << 16 | x_offset;
>  
> +	intel_crtc->adjusted_x = x_offset;
> +	intel_crtc->adjusted_y = y_offset;
> +
>  	I915_WRITE(PLANE_CTL(pipe, 0), plane_ctl);
>  	I915_WRITE(PLANE_OFFSET(pipe, 0), plane_offset);
>  	I915_WRITE(PLANE_SIZE(pipe, 0), plane_size);
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 02a755a..6054bcb 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -537,6 +537,8 @@ struct intel_crtc {
>  	 * gen4+ this only adjusts up to a tile, offsets within a tile are
>  	 * handled in the hw itself (with the TILEOFF register). */
>  	unsigned long dspaddr_offset;
> +	int adjusted_x;
> +	int adjusted_y;
>  
>  	struct drm_i915_gem_object *cursor_bo;
>  	uint32_t cursor_addr;
> diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
> index a3a97f2..2319dc5 100644
> --- a/drivers/gpu/drm/i915/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> @@ -41,6 +41,19 @@
>  #include "intel_drv.h"
>  #include "i915_drv.h"
>  
> +/*
> + * In some platforms where the CRTC's x:0/y:0 coordinates doesn't match the
> + * frontbuffer's x:0/y:0 coordinates we lie to the hardware about the plane's
> + * origin so the x and y offsets can actually fit the registers. As a
> + * consequence, the fence doesn't really start exactly at the display plane
> + * address we program because it starts at the real start of the buffer, so we
> + * have to take this into consideration here.
> + */
> +static unsigned int get_crtc_fence_y_offset(struct intel_crtc *crtc)
> +{
> +	return crtc->base.y - crtc->adjusted_y;
> +}

We may want to move over to using the plane state here in the future.
But for now it looks OK, so:

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>


> +
>  static void i8xx_fbc_disable(struct drm_i915_private *dev_priv)
>  {
>  	u32 fbc_ctl;
> @@ -97,7 +110,7 @@ static void i8xx_fbc_enable(struct intel_crtc *crtc)
>  		fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM | FBC_CTL_CPU_FENCE;
>  		fbc_ctl2 |= FBC_CTL_PLANE(crtc->plane);
>  		I915_WRITE(FBC_CONTROL2, fbc_ctl2);
> -		I915_WRITE(FBC_FENCE_OFF, crtc->base.y);
> +		I915_WRITE(FBC_FENCE_OFF, get_crtc_fence_y_offset(crtc));
>  	}
>  
>  	/* enable it... */
> @@ -135,7 +148,7 @@ static void g4x_fbc_enable(struct intel_crtc *crtc)
>  		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
>  	dpfc_ctl |= DPFC_CTL_FENCE_EN | obj->fence_reg;
>  
> -	I915_WRITE(DPFC_FENCE_YOFF, crtc->base.y);
> +	I915_WRITE(DPFC_FENCE_YOFF, get_crtc_fence_y_offset(crtc));
>  
>  	/* enable it... */
>  	I915_WRITE(DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
> @@ -177,6 +190,7 @@ static void ilk_fbc_enable(struct intel_crtc *crtc)
>  	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
>  	u32 dpfc_ctl;
>  	int threshold = dev_priv->fbc.threshold;
> +	unsigned int y_offset;
>  
>  	dev_priv->fbc.enabled = true;
>  
> @@ -200,7 +214,8 @@ static void ilk_fbc_enable(struct intel_crtc *crtc)
>  	if (IS_GEN5(dev_priv))
>  		dpfc_ctl |= obj->fence_reg;
>  
> -	I915_WRITE(ILK_DPFC_FENCE_YOFF, crtc->base.y);
> +	y_offset = get_crtc_fence_y_offset(crtc);
> +	I915_WRITE(ILK_DPFC_FENCE_YOFF, y_offset);
>  	I915_WRITE(ILK_FBC_RT_BASE, i915_gem_obj_ggtt_offset(obj) | ILK_FBC_RT_VALID);
>  	/* enable it... */
>  	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
> @@ -208,7 +223,7 @@ static void ilk_fbc_enable(struct intel_crtc *crtc)
>  	if (IS_GEN6(dev_priv)) {
>  		I915_WRITE(SNB_DPFC_CTL_SA,
>  			   SNB_CPU_FENCE_ENABLE | obj->fence_reg);
> -		I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->base.y);
> +		I915_WRITE(DPFC_CPU_FENCE_OFFSET, y_offset);
>  	}
>  
>  	intel_fbc_nuke(dev_priv);
> @@ -288,7 +303,7 @@ static void gen7_fbc_enable(struct intel_crtc *crtc)
>  
>  	I915_WRITE(SNB_DPFC_CTL_SA,
>  		   SNB_CPU_FENCE_ENABLE | obj->fence_reg);
> -	I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->base.y);
> +	I915_WRITE(DPFC_CPU_FENCE_OFFSET, get_crtc_fence_y_offset(crtc));
>  
>  	intel_fbc_nuke(dev_priv);
>  
> -- 
> 2.5.1
> 
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-- 
Ville Syrjälä
Intel OTC
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