[Intel-gfx] [PATCH 1/3] drm/i915: Enable FBC at Haswell.

[Ville Syrjälä]

On Mon, Apr 08, 2013 at 06:49:42PM -0300, Rodrigo Vivi wrote:
> This patch introduce Frame Buffer Compression (FBC) support for HSW.
> It adds a new function haswell_enable_fbc to avoid getting
> ironlake_enable_fbc messed with many IS_HASWELL checks.
> 
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.c |  1 +
>  drivers/gpu/drm/i915/i915_reg.h |  6 ++++++
>  drivers/gpu/drm/i915/intel_pm.c | 44 ++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 0cfc778..88fd6fb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -291,6 +291,7 @@ static const struct intel_device_info intel_haswell_m_info = {
>  	GEN7_FEATURES,
>  	.is_haswell = 1,
>  	.is_mobile = 1,
> +	.has_fbc = 1,
>  };
>  
>  static const struct pci_device_id pciidlist[] = {		/* aka */
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 5e91fbb..cb8e213 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -849,6 +849,12 @@
>  #define   SNB_CPU_FENCE_ENABLE	(1<<29)
>  #define DPFC_CPU_FENCE_OFFSET	0x100104
>  
> +/* Framebuffer compression for Haswell */
> +#define HSW_FBC_RT_BASE			0x7020
> +#define   HSW_FBC_RT_BASE_ADDR_SHIFT	12
> +
> +#define   HSW_DPFC_CTL_FENCE_EN		(1<<28)
> +#define   HSW_DPFC_CTL_DISABLE_SLB_INIT	(1<<15)
>  
>  /*
>   * GPIO regs
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 27f94cd..94e1c3a 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -253,6 +253,43 @@ static bool ironlake_fbc_enabled(struct drm_device *dev)
>  	return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
>  }
>  
> +static void haswell_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
> +{
> +	struct drm_device *dev = crtc->dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct drm_framebuffer *fb = crtc->fb;
> +	struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
> +	struct drm_i915_gem_object *obj = intel_fb->obj;
> +	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> +	int plane = intel_crtc->plane == 0 ? DPFC_CTL_PLANEA : DPFC_CTL_PLANEB;
> +	unsigned long stall_watermark = 200;
> +	u32 dpfc_ctl;
> +
> +	dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
> +	dpfc_ctl |= (plane | DPFC_CTL_LIMIT_1X);

Accroding to BSpec FBC is always tied to plane A. Bit 30 is MBZ.

Maybe fix up plane C FBC support for IVB while you're poking at the
general direction?

> +	dpfc_ctl |= (HSW_DPFC_CTL_FENCE_EN | obj->fence_reg);

The CPU fence field must be written with 0. SNB/IVB could do with the
same fix.

> +	dpfc_ctl |= HSW_DPFC_CTL_DISABLE_SLB_INIT;
> +	I915_WRITE(ILK_DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
> +		   (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
> +		   (interval << DPFC_RECOMP_TIMER_COUNT_SHIFT));
> +	I915_WRITE(HSW_FBC_RT_BASE,
> +		   obj->gtt_offset << HSW_FBC_RT_BASE_ADDR_SHIFT |
> +		   ILK_FBC_RT_VALID);
> +	/* enable it... */
> +	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
> +
> +	if (obj->fence_reg != I915_FENCE_REG_NONE) {
> +		I915_WRITE(SNB_DPFC_CTL_SA,
> +			   SNB_CPU_FENCE_ENABLE | obj->fence_reg);
> +		I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->y);
> +	} else
> +		I915_WRITE(SNB_DPFC_CTL_SA, ~SNB_CPU_FENCE_ENABLE);
> +
> +	sandybridge_blit_fbc_update(dev);
> +
> +	DRM_DEBUG_KMS("enabled fbc on plane %d\n", intel_crtc->plane);
> +}
> +
>  bool intel_fbc_enabled(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -4158,7 +4195,12 @@ void intel_init_pm(struct drm_device *dev)
>  	if (I915_HAS_FBC(dev)) {
>  		if (HAS_PCH_SPLIT(dev)) {
>  			dev_priv->display.fbc_enabled = ironlake_fbc_enabled;
> -			dev_priv->display.enable_fbc = ironlake_enable_fbc;
> +			if (IS_HASWELL(dev))
> +				dev_priv->display.enable_fbc =
> +					haswell_enable_fbc;
> +			else
> +				dev_priv->display.enable_fbc =
> +					ironlake_enable_fbc;
>  			dev_priv->display.disable_fbc = ironlake_disable_fbc;
>  		} else if (IS_GM45(dev)) {
>  			dev_priv->display.fbc_enabled = g4x_fbc_enabled;
> -- 
> 1.8.1.4
> 
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-- 
Ville Syrjälä
Intel OTC