Re: [PATCH v2 2/2] drm/i915/gen9: Add support for pipe background color (v2)

[Matt Roper <matthew.d.roper@intel.com>]

On Thu, Feb 11, 2016 at 12:00:50PM +0200, Ville Syrjälä wrote:
> On Wed, Feb 10, 2016 at 06:32:59PM -0800, Matt Roper wrote:
> > Gen9 platforms allow CRTC's to be programmed with a background/canvas
> > color below the programmable planes.  Let's expose this as a property to
> > allow userspace to program a desired value.
> > 
> > This patch is based on earlier work by Chandra Konduru; unfortunately
> > the driver has evolved so much since his patches were written (in the
> > pre-atomic era) that the functionality had to be pretty much completely
> > rewritten for the new i915 atomic internals.
> > 
> > v2:
> >  - Set initial background color (black) via proper helper function (Bob)
> >  - Fix debugfs output
> >  - General rebasing
> > 
> > Cc: Chandra Konduru <chandra.konduru@intel.com>
> > Cc: Bob Paauwe <bob.j.paauwe@intel.com>
> > Cc: dri-devel@lists.freedesktop.org
> > Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> > ---
> >  Documentation/DocBook/gpu.tmpl       | 10 +++++++-
> >  drivers/gpu/drm/i915/i915_debugfs.c  |  8 +++++++
> >  drivers/gpu/drm/i915/i915_reg.h      |  9 +++++++
> >  drivers/gpu/drm/i915/intel_display.c | 46 ++++++++++++++++++++++++++++++++++++
> >  4 files changed, 72 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
> > index fe6b36a..9e003cd 100644
> > --- a/Documentation/DocBook/gpu.tmpl
> > +++ b/Documentation/DocBook/gpu.tmpl
> > @@ -2092,7 +2092,7 @@ void intel_crt_init(struct drm_device *dev)
> >  	<td valign="top" >TBD</td>
> >  	</tr>
> >  	<tr>
> > -	<td rowspan="20" valign="top" >i915</td>
> > +	<td rowspan="21" valign="top" >i915</td>
> >  	<td rowspan="2" valign="top" >Generic</td>
> >  	<td valign="top" >"Broadcast RGB"</td>
> >  	<td valign="top" >ENUM</td>
> > @@ -2108,6 +2108,14 @@ void intel_crt_init(struct drm_device *dev)
> >  	<td valign="top" >TBD</td>
> >  	</tr>
> >  	<tr>
> > +	<td rowspan="1" valign="top" >CRTC</td>
> > +	<td valign="top" >“background_color”</td>
> > +	<td valign="top" >RGBA</td>
> > +	<td valign="top" >&nbsp;</td>
> > +	<td valign="top" >CRTC</td>
> > +	<td valign="top" >Background color of regions not covered by a plane</td>
> > +	</tr>
> > +	<tr>
> >  	<td rowspan="17" valign="top" >SDVO-TV</td>
> >  	<td valign="top" >“mode”</td>
> >  	<td valign="top" >ENUM</td>
> > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> > index ec0c2a05e..e7352fc 100644
> > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > @@ -3104,6 +3104,14 @@ static int i915_display_info(struct seq_file *m, void *unused)
> >  			intel_scaler_info(m, crtc);
> >  			intel_plane_info(m, crtc);
> >  		}
> > +		if (INTEL_INFO(dev)->gen >= 9 && pipe_config->base.active) {
> > +			struct drm_rgba background = pipe_config->base.background_color;
> > +
> > +			seq_printf(m, "\tbackground color (10bpc): r=%x g=%x b=%x\n",
> > +				   DRM_RGBA_REDBITS(background, 10),
> > +				   DRM_RGBA_GREENBITS(background, 10),
> > +				   DRM_RGBA_BLUEBITS(background, 10));
> > +		}
> >  
> >  		seq_printf(m, "\tunderrun reporting: cpu=%s pch=%s \n",
> >  			   yesno(!crtc->cpu_fifo_underrun_disabled),
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 144586e..b0b014d 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -7649,6 +7649,15 @@ enum skl_disp_power_wells {
> >  #define PIPE_CSC_POSTOFF_ME(pipe)	_MMIO_PIPE(pipe, _PIPE_A_CSC_POSTOFF_ME, _PIPE_B_CSC_POSTOFF_ME)
> >  #define PIPE_CSC_POSTOFF_LO(pipe)	_MMIO_PIPE(pipe, _PIPE_A_CSC_POSTOFF_LO, _PIPE_B_CSC_POSTOFF_LO)
> >  
> > +/* Skylake pipe bottom color */
> > +#define _PIPE_BOTTOM_COLOR_A        0x70034
> > +#define _PIPE_BOTTOM_COLOR_B        0x71034
> > +#define _PIPE_BOTTOM_COLOR_C        0x72034
> > +#define PIPE_BOTTOM_GAMMA_ENABLE   (1 << 31)
> > +#define PIPE_BOTTOM_CSC_ENABLE     (1 << 30)
> > +#define PIPE_BOTTOM_COLOR_MASK     0x3FFFFFFF
> > +#define PIPE_BOTTOM_COLOR(pipe) _MMIO_PIPE(pipe, _PIPE_BOTTOM_COLOR_A, _PIPE_BOTTOM_COLOR_B)
> > +
> >  /* MIPI DSI registers */
> >  
> >  #define _MIPI_PORT(port, a, c)	_PORT3(port, a, 0, c)	/* ports A and C only */
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 836bbdc..a616ac42 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -3299,6 +3299,8 @@ static void intel_update_pipe_config(struct intel_crtc *crtc,
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  	struct intel_crtc_state *pipe_config =
> >  		to_intel_crtc_state(crtc->base.state);
> > +	struct drm_rgba background = pipe_config->base.background_color;
> > +	uint32_t val;
> >  
> >  	/* drm_atomic_helper_update_legacy_modeset_state might not be called. */
> >  	crtc->base.mode = crtc->base.state->mode;
> > @@ -3335,6 +3337,26 @@ static void intel_update_pipe_config(struct intel_crtc *crtc,
> >  		else if (old_crtc_state->pch_pfit.enabled)
> >  			ironlake_pfit_disable(crtc, true);
> >  	}
> > +
> > +	if (INTEL_INFO(dev)->gen >= 9) {
> > +		/* BGR 16bpc ==> RGB 10bpc */
> > +		val = DRM_RGBA_REDBITS(background, 10) << 20
> > +		    | DRM_RGBA_GREENBITS(background, 10) << 10
> > +		    | DRM_RGBA_BLUEBITS(background, 10);
> 
> I'm not a fan of the drm_rgba thing having alpha in the low bits. It
> goes against the existing precedent set by eg. the colorkey ioctls
> where alpha (if it would be used) would be in the high bits. I think I
> complained about this before already, or maybe it was also about
> some BGR vs. RGB ordering thing?
> 
> Looks like drm_rgba isn't actually part of this series, and I can't see
> it in the tree either, so I guess it comes in via some other series?

drm_rgba was in patch #1 of this series; if that didn't come through for
you, it's in patchwork here:
  https://patchwork.freedesktop.org/patch/73224/

We could certainly flip around the internal ordering of bits, but I'm
not sure it really matters.  The whole point of drm_rgba is to be
somewhat opaque so that drivers don't try to work directly on the
internal representation (and potentially misinterpret the format).


Matt

> 
> > +
> > +		/*
> > +		 * Set CSC and gamma for bottom color.
> > +		 *
> > +		 * FIXME:  We turn these on unconditionally for now to match
> > +		 * how we've setup the various planes.  Once the color
> > +		 * management framework lands, it may or may not choose to
> > +		 * set these bits.
> > +		 */
> > +		val |= PIPE_BOTTOM_CSC_ENABLE;
> > +		val |= PIPE_BOTTOM_GAMMA_ENABLE;
> > +
> > +		I915_WRITE(PIPE_BOTTOM_COLOR(crtc->pipe), val);
> > +	}
> >  }
> >  
> >  static void intel_fdi_normal_train(struct drm_crtc *crtc)
> > @@ -12032,6 +12054,9 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
> >  							 pipe_config);
> >  	}
> >  
> > +	if (crtc->state->background_color.v != crtc_state->background_color.v)
> > +		pipe_config->update_pipe = true;
> > +
> >  	return ret;
> >  }
> >  
> > @@ -13660,6 +13685,7 @@ static const struct drm_crtc_funcs intel_crtc_funcs = {
> >  	.set_config = drm_atomic_helper_set_config,
> >  	.destroy = intel_crtc_destroy,
> >  	.page_flip = intel_crtc_page_flip,
> > +	.set_property = drm_atomic_helper_crtc_set_property,
> >  	.atomic_duplicate_state = intel_crtc_duplicate_state,
> >  	.atomic_destroy_state = intel_crtc_destroy_state,
> >  };
> > @@ -14254,6 +14280,20 @@ static void skl_init_scalers(struct drm_device *dev, struct intel_crtc *intel_cr
> >  	scaler_state->scaler_id = -1;
> >  }
> >  
> > +static void intel_create_background_color_property(struct drm_device *dev,
> > +						   struct intel_crtc *crtc)
> > +{
> > +	if (!dev->mode_config.prop_background_color)
> > +		dev->mode_config.prop_background_color =
> > +			drm_mode_create_background_color_property(dev);
> > +	if (!dev->mode_config.prop_background_color)
> > +		return;
> > +
> > +	drm_object_attach_property(&crtc->base.base,
> > +				   dev->mode_config.prop_background_color,
> > +				   crtc->base.state->background_color.v);
> > +}
> > +
> >  static void intel_crtc_init(struct drm_device *dev, int pipe)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -14329,6 +14369,12 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
> >  	drm_crtc_helper_add(&intel_crtc->base, &intel_helper_funcs);
> >  
> >  	WARN_ON(drm_crtc_index(&intel_crtc->base) != intel_crtc->pipe);
> > +
> > +	if (INTEL_INFO(dev)->gen >= 9) {
> > +		crtc_state->base.background_color = drm_rgba(16, 0, 0, 0, 0);
> > +		intel_create_background_color_property(dev, intel_crtc);
> > +	}
> > +
> >  	return;
> >  
> >  fail:
> > -- 
> > 2.1.4
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795
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