Nouveau - May 2018 - [PATCH 3/3] drm/vc4: Attach underscan props to the HDMI connector

Hello,

This is an attempt at providing generic support for underscan connector
props. We already have 3 drivers defining the same underscan, underscan
vborder and underscan hborder properties (amd, radeon and nouveau) and
I am about to add a new one, hence my proposal to put the prop parsing
code in the core and add ->underscan fields to drm_connector_state.

Note that I use this new infrastructure to support underscan in VC4
(path 2 and 3) but did not patch existing drivers yet, mainly because I
don't want to do this work before making sure I got the generic bits
right.

Regards,

Boris 

Boris Brezillon (3):
  drm/connector: Add generic underscan properties
  drm/vc4: Take underscan setup into account when updating planes
  drm/vc4: Attach underscan props to the HDMI connector

 drivers/gpu/drm/drm_atomic.c    |  12 ++++
 drivers/gpu/drm/drm_connector.c | 120 ++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_hdmi.c  |  25 +++++++++
 drivers/gpu/drm/vc4/vc4_plane.c |  49 +++++++++++++++-
 include/drm/drm_connector.h     |  78 ++++++++++++++++++++++++++
 5 files changed, 283 insertions(+), 1 deletion(-)

-- 
2.14.1

We have 3 drivers defining the "underscan", "underscan
hborder" and
"underscan vborder" properties (radeon, amd and nouveau) and we are
about to add the same kind of thing in VC4.

Define generic underscan props and add new fields to the drm_connector
state so that the property parsing logic can be shared by all DRM
drivers.

A driver can now attach underscan properties to its connector through
the drm_connector_attach_underscan_properties() helper, and can
check/apply the underscan setup based on the
drm_connector_state->underscan fields.

Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
---
 drivers/gpu/drm/drm_atomic.c    |  12 ++++
 drivers/gpu/drm/drm_connector.c | 120 ++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_connector.h     |  78 ++++++++++++++++++++++++++
 3 files changed, 210 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index dc850b4b6e21..b7312bd172c9 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1278,6 +1278,12 @@ static int drm_atomic_connector_set_property(struct
drm_connector *connector,
 			return -EINVAL;
 		}
 		state->content_protection = val;
+	} else if (property == connector->underscan_mode_property) {
+		state->underscan.mode = val;
+	} else if (property == connector->underscan_hborder_property) {
+		state->underscan.hborder = val;
+	} else if (property == connector->underscan_vborder_property) {
+		state->underscan.vborder = val;
 	} else if (connector->funcs->atomic_set_property) {
 		return connector->funcs->atomic_set_property(connector,
 				state, property, val);
@@ -1359,6 +1365,12 @@ drm_atomic_connector_get_property(struct drm_connector
*connector,
 		*val = state->scaling_mode;
 	} else if (property == connector->content_protection_property) {
 		*val = state->content_protection;
+	} else if (property == connector->underscan_mode_property) {
+		*val = state->underscan.mode;
+	} else if (property == connector->underscan_hborder_property) {
+		*val = state->underscan.hborder;
+	} else if (property == connector->underscan_vborder_property) {
+		*val = state->underscan.vborder;
 	} else if (connector->funcs->atomic_get_property) {
 		return connector->funcs->atomic_get_property(connector,
 				state, property, val);
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index dfc8ca1e9413..9937390b8a25 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -914,6 +914,31 @@ DRM_ENUM_NAME_FN(drm_get_content_protection_name,
drm_cp_enum_list)
  *	can also expose this property to external outputs, in which case they
  *	must support "None", which should be the default (since external
screens
  *	have a built-in scaler).
+ *
+ * underscan:
+ *	This properties defines whether underscan is activated or not, and when
+ *	it is activated, how the horizontal and vertical borders are calculated:
+ *
+ *	off:
+ *		Underscan is disabled. The output image shouldn't be scaled to
+ *		take screen borders into account.
+ *	on:
+ *		Underscan is activated and horizontal and vertical borders are
+ *		specified through the "underscan hborder" and
+ *		"underscan vborder" properties.
+ *	auto:
+ *		Underscan is activated and horizontal and vertical borders are
+ *		automatically chosen by the driver.
+ *
+ * underscan hborder:
+ *	Horizontal border expressed in pixels. The border is symmetric, which
+ *	means you'll have half of this value placed on the left and the other
+ *	half on the right.
+ *
+ * underscan vborder:
+ *	Vertical border expressed in pixels. The border is symmetric, which
+ *	means you'll have half of this value placed on the top and the other
+ *	half on the bottom.
  */
 
 int drm_connector_create_standard_properties(struct drm_device *dev)
@@ -1108,6 +1133,101 @@ int drm_mode_create_tv_properties(struct drm_device
*dev,
 }
 EXPORT_SYMBOL(drm_mode_create_tv_properties);
 
+static const struct drm_prop_enum_list drm_underscan_mode_enum_list[] = {
+	{ DRM_UNDERSCAN_OFF, "off" },
+	{ DRM_UNDERSCAN_ON, "on" },
+	{ DRM_UNDERSCAN_AUTO, "auto" },
+};
+
+/**
+ * drm_connector_attach_underscan_properties - attach atomic underscan
+ *					       properties
+ * @connector: connector to attach underscan mode properties on.
+ * @mode_mask: bitmask of %DRM_UNDERSCAN_XX modes encoding the supported
+ *	       underscan modes.
+ * @max_hborder: maximum size of the horizontal border expressed in pixels.
+ *		 Should be > 0.
+ * @max_vborder: maximum size of the vertical border expressed in pixels.
+ *		 Should be > 0.
+ *
+ * This is used to add support for underscan to atomic drivers.
+ * The underscan config will be set to &drm_connector_state.underscan
+ * and can be used from &drm_connector_helper_funcs->atomic_check for
+ * validation.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_attach_underscan_properties(struct drm_connector *connector,
+					      u32 mode_mask, u64 max_hborder,
+					      u64 max_vborder)
+{
+	unsigned int i, nmodes = ARRAY_SIZE(drm_underscan_mode_enum_list);
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop;
+
+	if (!max_hborder || !max_vborder)
+		return -EINVAL;
+
+	if (!hweight32(mode_mask) || (mode_mask & ~GENMASK(nmodes - 1, 0)))
+		return -EINVAL;
+
+	prop = drm_property_create(dev, DRM_MODE_PROP_ENUM, "underscan",
+				   hweight32(mode_mask));
+	if (!prop)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(drm_underscan_mode_enum_list); i++) {
+		const struct drm_prop_enum_list *entry;
+		int ret;
+
+		if (!(BIT(i) & mode_mask))
+			continue;
+
+		entry = &drm_underscan_mode_enum_list[i];
+		ret = drm_property_add_enum(prop, entry->type, entry->name);
+		if (ret)
+			goto err_free_mode_prop;
+	}
+
+	connector->underscan_mode_property = prop;
+
+	prop = drm_property_create_range(dev, 0, "underscan hborder", 0,
+					 max_hborder);
+	if (!prop)
+		goto err_free_mode_prop;
+
+	connector->underscan_hborder_property = prop;
+
+	prop = drm_property_create_range(dev, 0, "underscan vborder", 0,
+					 max_vborder);
+	if (!prop)
+		goto err_free_hborder_prop;
+
+	connector->underscan_vborder_property = prop;
+
+	drm_object_attach_property(&connector->base,
+				   connector->underscan_mode_property,
+				   DRM_UNDERSCAN_OFF);
+	drm_object_attach_property(&connector->base,
+				   connector->underscan_hborder_property, 0);
+	drm_object_attach_property(&connector->base,
+				   connector->underscan_vborder_property, 0);
+
+	return 0;
+
+err_free_hborder_prop:
+	drm_property_destroy(dev, connector->underscan_hborder_property);
+	connector->underscan_hborder_property = NULL;
+
+err_free_mode_prop:
+	drm_property_destroy(dev, connector->underscan_mode_property);
+	connector->underscan_mode_property = NULL;
+
+	return -ENOMEM;
+}
+EXPORT_SYMBOL(drm_connector_attach_underscan_properties);
+
 /**
  * drm_mode_create_scaling_mode_property - create scaling mode property
  * @dev: DRM device
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 675cc3f8cf85..46380ee6d4ee 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -372,6 +372,52 @@ struct drm_tv_connector_state {
 	unsigned int hue;
 };
 
+/**
+ * enum drm_underscan_mode - Underscan mode
+ *
+ * This enum is used to track the underscan mode.
+ *
+ * @DRM_UNDERSCAN_OFF: No underscan applied, the output image will be unchanged
+ * @DRM_UNDERSCAN_ON: Underscan is enabled, and horizontal/vertical border size
+ *		      are specified through the &struct_drm_underscan->hborder
+ *		      and &struct_drm_underscan->vborder fields.
+ * @DRM_UNDERSCAN_AUTO: Underscan is enabled and
&struct_drm_underscan->hborder
+ *			and &struct_drm_underscan->vborder are guessed by the
+ *			driver.
+ */
+enum drm_underscan_mode {
+	DRM_UNDERSCAN_OFF,
+	DRM_UNDERSCAN_ON,
+	DRM_UNDERSCAN_AUTO,
+};
+
+/**
+ * struct drm_underscan - Underscan properties attached to a connector state
+ *
+ * This can be used to tell the CRTC how the image should be scaled/placed in
+ * order to cover fit in the display connected through this connector. Most of
+ * the time used to address situations where the display borders are hidden.
+ * Can also be used to compensate overscan done on the display side.
+ */
+struct drm_underscan {
+	/**
+	 * @mode: Underscan mode.
+	 */
+	enum drm_underscan_mode mode;
+
+	/**
+	 * @hborder: Horizontal border. This values encodes both the left and
+	 * right borders: left_border = right_border = hborder / 2.
+	 */
+	unsigned int hborder;
+
+	/**
+	 * @vborder: Vertical border. This values encodes both the top and
+	 * bottom borders: top_border = bottom_border = vborder / 2.
+	 */
+	unsigned int vborder;
+};
+
 /**
  * struct drm_connector_state - mutable connector state
  * @connector: backpointer to the connector
@@ -429,6 +475,12 @@ struct drm_connector_state {
 	 * protection. This is most commonly used for HDCP.
 	 */
 	unsigned int content_protection;
+
+	/**
+	 * @underscan: Underscan information. Most commonly used to adjust
+	 * image when the display is doing overscan.
+	 */
+	struct drm_underscan underscan;
 };
 
 /**
@@ -892,6 +944,29 @@ struct drm_connector {
 	 */
 	struct drm_property_blob *tile_blob_ptr;
 
+	/**
+	 * @underscan_mode_property: Optional connector underscan mode. Used by
+	 * the driver to scale the output image and compensate an overscan done
+	 * on the display side.
+	 */
+	struct drm_property *underscan_mode_property;
+
+	/**
+	 * @underscan_hborder_property: Optional connector underscan horizontal
+	 * border (expressed in pixels). Used by the driver to adjust the
+	 * output image position and compensate an overscan done on the display
+	 * side.
+	 */
+	struct drm_property *underscan_hborder_property;
+
+	/**
+	 * @underscan_hborder_property: Optional connector underscan vertical
+	 * border (expressed in pixels). Used by the driver to adjust the
+	 * output image position and compensate an overscan done on the display
+	 * side.
+	 */
+	struct drm_property *underscan_vborder_property;
+
 /* should we poll this connector for connects and disconnects */
 /* hot plug detectable */
 #define DRM_CONNECTOR_POLL_HPD (1 << 0)
@@ -1088,6 +1163,9 @@ int drm_mode_create_dvi_i_properties(struct drm_device
*dev);
 int drm_mode_create_tv_properties(struct drm_device *dev,
 				  unsigned int num_modes,
 				  const char * const modes[]);
+int drm_connector_attach_underscan_properties(struct drm_connector *connector,
+					      u32 mode_mask, u64 max_hborder,
+					      u64 max_vborder);
 int drm_mode_create_scaling_mode_property(struct drm_device *dev);
 int drm_connector_attach_scaling_mode_property(struct drm_connector *connector,
 					       u32 scaling_mode_mask);
-- 
2.14.1

Applying an underscan setup is just a matter of scaling all planes
appropriately and adjusting the CRTC X/Y offset to account for the
horizontal and vertical border.

Create an vc4_plane_underscan_adj() function doing that and call it from
vc4_plane_setup_clipping_and_scaling() so that we are ready to attach
underscan properties to the HDMI connector.

Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
---
 drivers/gpu/drm/vc4/vc4_plane.c | 49 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index 71d44c357d35..7d5667b1f990 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -258,6 +258,49 @@ static u32 vc4_get_scl_field(struct drm_plane_state *state,
int plane)
 	}
 }
 
+static int vc4_plane_underscan_adj(struct drm_plane_state *pstate)
+{
+	struct vc4_plane_state *vc4_pstate = to_vc4_plane_state(pstate);
+	struct drm_connector_state *conn_state = NULL;
+	struct drm_connector *conn;
+	struct drm_crtc_state *crtc_state;
+	int i;
+
+	for_each_new_connector_in_state(pstate->state, conn, conn_state, i) {
+		if (conn_state->crtc == pstate->crtc)
+			break;
+	}
+
+	if (i == pstate->state->num_connector)
+		return 0;
+
+	if (conn_state->underscan.mode != DRM_UNDERSCAN_ON)
+		return 0;
+
+	crtc_state = drm_atomic_get_new_crtc_state(pstate->state,
+						   pstate->crtc);
+
+	if (conn_state->underscan.hborder >= crtc_state->mode.hdisplay ||
+	    conn_state->underscan.vborder >= crtc_state->mode.vdisplay)
+		return -EINVAL;
+
+	vc4_pstate->crtc_x += conn_state->underscan.hborder / 2;
+	vc4_pstate->crtc_y += conn_state->underscan.vborder / 2;
+	vc4_pstate->crtc_w = (vc4_pstate->crtc_w *
+			      (crtc_state->mode.hdisplay -
+			       conn_state->underscan.hborder)) /
+			     crtc_state->mode.hdisplay;
+	vc4_pstate->crtc_h = (vc4_pstate->crtc_h *
+			      (crtc_state->mode.vdisplay -
+			       conn_state->underscan.vborder)) /
+			     crtc_state->mode.vdisplay;
+
+	if (!vc4_pstate->crtc_w || !vc4_pstate->crtc_h)
+		return -EINVAL;
+
+	return 0;
+}
+
 static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state)
 {
 	struct drm_plane *plane = state->plane;
@@ -269,7 +312,7 @@ static int vc4_plane_setup_clipping_and_scaling(struct
drm_plane_state *state)
 	int num_planes = fb->format->num_planes;
 	u32 h_subsample = 1;
 	u32 v_subsample = 1;
-	int i;
+	int i, ret;
 
 	for (i = 0; i < num_planes; i++)
 		vc4_state->offsets[i] = bo->paddr + fb->offsets[i];
@@ -292,6 +335,10 @@ static int vc4_plane_setup_clipping_and_scaling(struct
drm_plane_state *state)
 	vc4_state->crtc_w = state->crtc_w;
 	vc4_state->crtc_h = state->crtc_h;
 
+	ret = vc4_plane_underscan_adj(state);
+	if (ret)
+		return ret;
+
 	vc4_state->x_scaling[0] = vc4_get_scaling_mode(vc4_state->src_w[0],
 						       vc4_state->crtc_w);
 	vc4_state->y_scaling[0] = vc4_get_scaling_mode(vc4_state->src_h[0],
-- 
2.14.1

Now that the plane code takes the underscan setup into account, we can
safely attach the underscan props to the HDMI connector.

We also take care of filling AVI infoframes correctly to expose the
top/botton/left/right bar.

Note that these underscan props match pretty well the
overscan_{left,right,top,bottom} properties defined in config.txt and
parsed by the VC4 firmware.

Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 1a6db291d48b..17464b5981f9 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -323,6 +323,16 @@ static struct drm_connector *vc4_hdmi_connector_init(struct
drm_device *dev,
 			   DRM_MODE_CONNECTOR_HDMIA);
 	drm_connector_helper_add(connector, &vc4_hdmi_connector_helper_funcs);
 
+	/* The hborder and vborder limit is arbitrarily set to 1024 which
+	 * should be more than enough for real use cases. Note that the actual
+	 * limitation comes from the display mode:
+	 *	hborder < hdisplay && vborder < vdisplay
+	 */
+	drm_connector_attach_underscan_properties(connector,
+						  BIT(DRM_UNDERSCAN_OFF) |
+						  BIT(DRM_UNDERSCAN_ON),
+						  1024, 1024);
+
 	connector->polled = (DRM_CONNECTOR_POLL_CONNECT |
 			     DRM_CONNECTOR_POLL_DISCONNECT);
 
@@ -408,6 +418,9 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder
*encoder,
 static void vc4_hdmi_set_avi_infoframe(struct drm_encoder *encoder)
 {
 	struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
+	struct vc4_dev *vc4 = encoder->dev->dev_private;
+	struct vc4_hdmi *hdmi = vc4->hdmi;
+	struct drm_connector_state *cstate = hdmi->connector->state;
 	struct drm_crtc *crtc = encoder->crtc;
 	const struct drm_display_mode *mode = &crtc->state->adjusted_mode;
 	union hdmi_infoframe frame;
@@ -426,6 +439,18 @@ static void vc4_hdmi_set_avi_infoframe(struct drm_encoder
*encoder)
 					   vc4_encoder->rgb_range_selectable,
 					   false);
 
+	if (cstate->underscan.mode == DRM_UNDERSCAN_ON) {
+		if (cstate->underscan.hborder) {
+			frame.avi.right_bar = cstate->underscan.hborder / 2;
+			frame.avi.left_bar = frame.avi.right_bar;
+		}
+
+		if (cstate->underscan.vborder) {
+			frame.avi.top_bar = cstate->underscan.vborder / 2;
+			frame.avi.bottom_bar = frame.avi.top_bar;
+		}
+	}
+
 	vc4_hdmi_write_infoframe(encoder, &frame);
 }
 
-- 
2.14.1

On Mon, May 07, 2018 at 04:44:32PM +0200, Boris Brezillon
wrote:
> We have 3 drivers defining the "underscan", "underscan
hborder" and
> "underscan vborder" properties (radeon, amd and nouveau) and we
are
> about to add the same kind of thing in VC4.
> 
> Define generic underscan props and add new fields to the drm_connector
> state so that the property parsing logic can be shared by all DRM
> drivers.
> 
> A driver can now attach underscan properties to its connector through
> the drm_connector_attach_underscan_properties() helper, and can
> check/apply the underscan setup based on the
> drm_connector_state->underscan fields.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
> ---
>  drivers/gpu/drm/drm_atomic.c    |  12 ++++
>  drivers/gpu/drm/drm_connector.c | 120
++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_connector.h     |  78 ++++++++++++++++++++++++++
>  3 files changed, 210 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index dc850b4b6e21..b7312bd172c9 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -1278,6 +1278,12 @@ static int drm_atomic_connector_set_property(struct
drm_connector *connector,
>  			return -EINVAL;
>  		}
>  		state->content_protection = val;
> +	} else if (property == connector->underscan_mode_property) {
> +		state->underscan.mode = val;
> +	} else if (property == connector->underscan_hborder_property) {
> +		state->underscan.hborder = val;
> +	} else if (property == connector->underscan_vborder_property) {
> +		state->underscan.vborder = val;
>  	} else if (connector->funcs->atomic_set_property) {
>  		return connector->funcs->atomic_set_property(connector,
>  				state, property, val);
> @@ -1359,6 +1365,12 @@ drm_atomic_connector_get_property(struct
drm_connector *connector,
>  		*val = state->scaling_mode;
>  	} else if (property == connector->content_protection_property) {
>  		*val = state->content_protection;
> +	} else if (property == connector->underscan_mode_property) {
> +		*val = state->underscan.mode;
> +	} else if (property == connector->underscan_hborder_property) {
> +		*val = state->underscan.hborder;
> +	} else if (property == connector->underscan_vborder_property) {
> +		*val = state->underscan.vborder;
>  	} else if (connector->funcs->atomic_get_property) {
>  		return connector->funcs->atomic_get_property(connector,
>  				state, property, val);
> diff --git a/drivers/gpu/drm/drm_connector.c
b/drivers/gpu/drm/drm_connector.c
> index dfc8ca1e9413..9937390b8a25 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -914,6 +914,31 @@ DRM_ENUM_NAME_FN(drm_get_content_protection_name,
drm_cp_enum_list)
>   *	can also expose this property to external outputs, in which case they
>   *	must support "None", which should be the default (since
external screens
>   *	have a built-in scaler).
> + *
> + * underscan:
> + *	This properties defines whether underscan is activated or not, and when
> + *	it is activated, how the horizontal and vertical borders are
calculated:
> + *
> + *	off:
> + *		Underscan is disabled. The output image shouldn't be scaled to
> + *		take screen borders into account.
> + *	on:
> + *		Underscan is activated and horizontal and vertical borders are
> + *		specified through the "underscan hborder" and
> + *		"underscan vborder" properties.
How is the output scaled? What does the user mode hdisplay/vdisplay mean
in this case? What if I want underscan without scaling?
> + *	auto:
> + *		Underscan is activated and horizontal and vertical borders are
> + *		automatically chosen by the driver.
Seems overly vague to be useful. You didn't even seem to implement it
for vc4.
> + *
> + * underscan hborder:
> + *	Horizontal border expressed in pixels. The border is symmetric, which
> + *	means you'll have half of this value placed on the left and the
other
> + *	half on the right.
Seems like a slightly odd way to specify this. I think for the TV margins
we have one value for each edge.
> + *
> + * underscan vborder:
> + *	Vertical border expressed in pixels. The border is symmetric, which
> + *	means you'll have half of this value placed on the top and the
other
> + *	half on the bottom.
>   */
>  
>  int drm_connector_create_standard_properties(struct drm_device *dev)
> @@ -1108,6 +1133,101 @@ int drm_mode_create_tv_properties(struct drm_device
*dev,
>  }
>  EXPORT_SYMBOL(drm_mode_create_tv_properties);
>  
> +static const struct drm_prop_enum_list drm_underscan_mode_enum_list[] = {
> +	{ DRM_UNDERSCAN_OFF, "off" },
> +	{ DRM_UNDERSCAN_ON, "on" },
> +	{ DRM_UNDERSCAN_AUTO, "auto" },
> +};
> +
> +/**
> + * drm_connector_attach_underscan_properties - attach atomic underscan
> + *					       properties
> + * @connector: connector to attach underscan mode properties on.
> + * @mode_mask: bitmask of %DRM_UNDERSCAN_XX modes encoding the supported
> + *	       underscan modes.
> + * @max_hborder: maximum size of the horizontal border expressed in
pixels.
> + *		 Should be > 0.
> + * @max_vborder: maximum size of the vertical border expressed in pixels.
> + *		 Should be > 0.
> + *
> + * This is used to add support for underscan to atomic drivers.
> + * The underscan config will be set to &drm_connector_state.underscan
> + * and can be used from &drm_connector_helper_funcs->atomic_check
for
> + * validation.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_connector_attach_underscan_properties(struct drm_connector
*connector,
> +					      u32 mode_mask, u64 max_hborder,
> +					      u64 max_vborder)
> +{
> +	unsigned int i, nmodes = ARRAY_SIZE(drm_underscan_mode_enum_list);
> +	struct drm_device *dev = connector->dev;
> +	struct drm_property *prop;
> +
> +	if (!max_hborder || !max_vborder)
> +		return -EINVAL;
> +
> +	if (!hweight32(mode_mask) || (mode_mask & ~GENMASK(nmodes - 1, 0)))
> +		return -EINVAL;
> +
> +	prop = drm_property_create(dev, DRM_MODE_PROP_ENUM,
"underscan",
> +				   hweight32(mode_mask));
> +	if (!prop)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < ARRAY_SIZE(drm_underscan_mode_enum_list); i++) {
> +		const struct drm_prop_enum_list *entry;
> +		int ret;
> +
> +		if (!(BIT(i) & mode_mask))
> +			continue;
> +
> +		entry = &drm_underscan_mode_enum_list[i];
> +		ret = drm_property_add_enum(prop, entry->type, entry->name);
> +		if (ret)
> +			goto err_free_mode_prop;
> +	}
> +
> +	connector->underscan_mode_property = prop;
> +
> +	prop = drm_property_create_range(dev, 0, "underscan hborder",
0,
> +					 max_hborder);
> +	if (!prop)
> +		goto err_free_mode_prop;
> +
> +	connector->underscan_hborder_property = prop;
> +
> +	prop = drm_property_create_range(dev, 0, "underscan vborder",
0,
> +					 max_vborder);
> +	if (!prop)
> +		goto err_free_hborder_prop;
> +
> +	connector->underscan_vborder_property = prop;
> +
> +	drm_object_attach_property(&connector->base,
> +				   connector->underscan_mode_property,
> +				   DRM_UNDERSCAN_OFF);
> +	drm_object_attach_property(&connector->base,
> +				   connector->underscan_hborder_property, 0);
> +	drm_object_attach_property(&connector->base,
> +				   connector->underscan_vborder_property, 0);
> +
> +	return 0;
> +
> +err_free_hborder_prop:
> +	drm_property_destroy(dev, connector->underscan_hborder_property);
> +	connector->underscan_hborder_property = NULL;
> +
> +err_free_mode_prop:
> +	drm_property_destroy(dev, connector->underscan_mode_property);
> +	connector->underscan_mode_property = NULL;
> +
> +	return -ENOMEM;
> +}
> +EXPORT_SYMBOL(drm_connector_attach_underscan_properties);
> +
>  /**
>   * drm_mode_create_scaling_mode_property - create scaling mode property
>   * @dev: DRM device
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 675cc3f8cf85..46380ee6d4ee 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -372,6 +372,52 @@ struct drm_tv_connector_state {
>  	unsigned int hue;
>  };
>  
> +/**
> + * enum drm_underscan_mode - Underscan mode
> + *
> + * This enum is used to track the underscan mode.
> + *
> + * @DRM_UNDERSCAN_OFF: No underscan applied, the output image will be
unchanged
> + * @DRM_UNDERSCAN_ON: Underscan is enabled, and horizontal/vertical border
size
> + *		      are specified through the &struct_drm_underscan->hborder
> + *		      and &struct_drm_underscan->vborder fields.
> + * @DRM_UNDERSCAN_AUTO: Underscan is enabled and
&struct_drm_underscan->hborder
> + *			and &struct_drm_underscan->vborder are guessed by the
> + *			driver.
> + */
> +enum drm_underscan_mode {
> +	DRM_UNDERSCAN_OFF,
> +	DRM_UNDERSCAN_ON,
> +	DRM_UNDERSCAN_AUTO,
> +};
> +
> +/**
> + * struct drm_underscan - Underscan properties attached to a connector
state
> + *
> + * This can be used to tell the CRTC how the image should be scaled/placed
in
> + * order to cover fit in the display connected through this connector.
Most of
> + * the time used to address situations where the display borders are
hidden.
> + * Can also be used to compensate overscan done on the display side.
> + */
> +struct drm_underscan {
> +	/**
> +	 * @mode: Underscan mode.
> +	 */
> +	enum drm_underscan_mode mode;
> +
> +	/**
> +	 * @hborder: Horizontal border. This values encodes both the left and
> +	 * right borders: left_border = right_border = hborder / 2.
> +	 */
> +	unsigned int hborder;
> +
> +	/**
> +	 * @vborder: Vertical border. This values encodes both the top and
> +	 * bottom borders: top_border = bottom_border = vborder / 2.
> +	 */
> +	unsigned int vborder;
> +};
> +
>  /**
>   * struct drm_connector_state - mutable connector state
>   * @connector: backpointer to the connector
> @@ -429,6 +475,12 @@ struct drm_connector_state {
>  	 * protection. This is most commonly used for HDCP.
>  	 */
>  	unsigned int content_protection;
> +
> +	/**
> +	 * @underscan: Underscan information. Most commonly used to adjust
> +	 * image when the display is doing overscan.
> +	 */
> +	struct drm_underscan underscan;
>  };
>  
>  /**
> @@ -892,6 +944,29 @@ struct drm_connector {
>  	 */
>  	struct drm_property_blob *tile_blob_ptr;
>  
> +	/**
> +	 * @underscan_mode_property: Optional connector underscan mode. Used by
> +	 * the driver to scale the output image and compensate an overscan done
> +	 * on the display side.
> +	 */
> +	struct drm_property *underscan_mode_property;
> +
> +	/**
> +	 * @underscan_hborder_property: Optional connector underscan horizontal
> +	 * border (expressed in pixels). Used by the driver to adjust the
> +	 * output image position and compensate an overscan done on the display
> +	 * side.
> +	 */
> +	struct drm_property *underscan_hborder_property;
> +
> +	/**
> +	 * @underscan_hborder_property: Optional connector underscan vertical
> +	 * border (expressed in pixels). Used by the driver to adjust the
> +	 * output image position and compensate an overscan done on the display
> +	 * side.
> +	 */
> +	struct drm_property *underscan_vborder_property;
> +
>  /* should we poll this connector for connects and disconnects */
>  /* hot plug detectable */
>  #define DRM_CONNECTOR_POLL_HPD (1 << 0)
> @@ -1088,6 +1163,9 @@ int drm_mode_create_dvi_i_properties(struct
drm_device *dev);
>  int drm_mode_create_tv_properties(struct drm_device *dev,
>  				  unsigned int num_modes,
>  				  const char * const modes[]);
> +int drm_connector_attach_underscan_properties(struct drm_connector
*connector,
> +					      u32 mode_mask, u64 max_hborder,
> +					      u64 max_vborder);
>  int drm_mode_create_scaling_mode_property(struct drm_device *dev);
>  int drm_connector_attach_scaling_mode_property(struct drm_connector
*connector,
>  					       u32 scaling_mode_mask);
> -- 
> 2.14.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
-- 
Ville Syrjälä
Intel

On Mon, May 07, 2018 at 04:44:32PM +0200, Boris Brezillon
wrote:
> We have 3 drivers defining the "underscan", "underscan
hborder" and
> "underscan vborder" properties (radeon, amd and nouveau) and we
are
> about to add the same kind of thing in VC4.
> 
> Define generic underscan props and add new fields to the drm_connector
> state so that the property parsing logic can be shared by all DRM
> drivers.
> 
> A driver can now attach underscan properties to its connector through
> the drm_connector_attach_underscan_properties() helper, and can
> check/apply the underscan setup based on the
> drm_connector_state->underscan fields.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
> ---
>  drivers/gpu/drm/drm_atomic.c    |  12 ++++
>  drivers/gpu/drm/drm_connector.c | 120
++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_connector.h     |  78 ++++++++++++++++++++++++++
>  3 files changed, 210 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index dc850b4b6e21..b7312bd172c9 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -1278,6 +1278,12 @@ static int drm_atomic_connector_set_property(struct
drm_connector *connector,
>  			return -EINVAL;
>  		}
>  		state->content_protection = val;
> +	} else if (property == connector->underscan_mode_property) {
> +		state->underscan.mode = val;
> +	} else if (property == connector->underscan_hborder_property) {
> +		state->underscan.hborder = val;
> +	} else if (property == connector->underscan_vborder_property) {
> +		state->underscan.vborder = val;
>  	} else if (connector->funcs->atomic_set_property) {
>  		return connector->funcs->atomic_set_property(connector,
>  				state, property, val);
> @@ -1359,6 +1365,12 @@ drm_atomic_connector_get_property(struct
drm_connector *connector,
>  		*val = state->scaling_mode;
>  	} else if (property == connector->content_protection_property) {
>  		*val = state->content_protection;
> +	} else if (property == connector->underscan_mode_property) {
> +		*val = state->underscan.mode;
> +	} else if (property == connector->underscan_hborder_property) {
> +		*val = state->underscan.hborder;
> +	} else if (property == connector->underscan_vborder_property) {
> +		*val = state->underscan.vborder;
>  	} else if (connector->funcs->atomic_get_property) {
>  		return connector->funcs->atomic_get_property(connector,
>  				state, property, val);
> diff --git a/drivers/gpu/drm/drm_connector.c
b/drivers/gpu/drm/drm_connector.c
> index dfc8ca1e9413..9937390b8a25 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -914,6 +914,31 @@ DRM_ENUM_NAME_FN(drm_get_content_protection_name,
drm_cp_enum_list)
>   *	can also expose this property to external outputs, in which case they
>   *	must support "None", which should be the default (since
external screens
>   *	have a built-in scaler).
I think a new section here would be good, to make it more obvious this is
a group of properties. Plus a reference to
drm_connector_attach_underscan_properties().
> + *
> + * underscan:
> + *	This properties defines whether underscan is activated or not, and when
> + *	it is activated, how the horizontal and vertical borders are
calculated:
> + *
> + *	off:
> + *		Underscan is disabled. The output image shouldn't be scaled to
> + *		take screen borders into account.
> + *	on:
> + *		Underscan is activated and horizontal and vertical borders are
> + *		specified through the "underscan hborder" and
> + *		"underscan vborder" properties.
> + *	auto:
> + *		Underscan is activated and horizontal and vertical borders are
> + *		automatically chosen by the driver.
> + *
> + * underscan hborder:
> + *	Horizontal border expressed in pixels. The border is symmetric, which
> + *	means you'll have half of this value placed on the left and the
other
> + *	half on the right.
> + *
> + * underscan vborder:
> + *	Vertical border expressed in pixels. The border is symmetric, which
> + *	means you'll have half of this value placed on the top and the
other
> + *	half on the bottom.
>   */
>  
>  int drm_connector_create_standard_properties(struct drm_device *dev)
> @@ -1108,6 +1133,101 @@ int drm_mode_create_tv_properties(struct drm_device
*dev,
>  }
>  EXPORT_SYMBOL(drm_mode_create_tv_properties);
>  
> +static const struct drm_prop_enum_list drm_underscan_mode_enum_list[] = {
> +	{ DRM_UNDERSCAN_OFF, "off" },
> +	{ DRM_UNDERSCAN_ON, "on" },
> +	{ DRM_UNDERSCAN_AUTO, "auto" },
> +};
> +
> +/**
> + * drm_connector_attach_underscan_properties - attach atomic underscan
> + *					       properties
> + * @connector: connector to attach underscan mode properties on.
> + * @mode_mask: bitmask of %DRM_UNDERSCAN_XX modes encoding the supported
> + *	       underscan modes.
> + * @max_hborder: maximum size of the horizontal border expressed in
pixels.
> + *		 Should be > 0.
> + * @max_vborder: maximum size of the vertical border expressed in pixels.
> + *		 Should be > 0.
> + *
> + * This is used to add support for underscan to atomic drivers.
> + * The underscan config will be set to &drm_connector_state.underscan
> + * and can be used from &drm_connector_helper_funcs->atomic_check
for
> + * validation.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_connector_attach_underscan_properties(struct drm_connector
*connector,
> +					      u32 mode_mask, u64 max_hborder,
> +					      u64 max_vborder)
> +{
> +	unsigned int i, nmodes = ARRAY_SIZE(drm_underscan_mode_enum_list);
> +	struct drm_device *dev = connector->dev;
> +	struct drm_property *prop;
> +
> +	if (!max_hborder || !max_vborder)
> +		return -EINVAL;
> +
> +	if (!hweight32(mode_mask) || (mode_mask & ~GENMASK(nmodes - 1, 0)))
> +		return -EINVAL;
> +
> +	prop = drm_property_create(dev, DRM_MODE_PROP_ENUM,
"underscan",
> +				   hweight32(mode_mask));
> +	if (!prop)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < ARRAY_SIZE(drm_underscan_mode_enum_list); i++) {
> +		const struct drm_prop_enum_list *entry;
> +		int ret;
> +
> +		if (!(BIT(i) & mode_mask))
> +			continue;
> +
> +		entry = &drm_underscan_mode_enum_list[i];
> +		ret = drm_property_add_enum(prop, entry->type, entry->name);
> +		if (ret)
> +			goto err_free_mode_prop;
> +	}
> +
> +	connector->underscan_mode_property = prop;
> +
> +	prop = drm_property_create_range(dev, 0, "underscan hborder",
0,
> +					 max_hborder);
> +	if (!prop)
> +		goto err_free_mode_prop;
> +
> +	connector->underscan_hborder_property = prop;
> +
> +	prop = drm_property_create_range(dev, 0, "underscan vborder",
0,
> +					 max_vborder);
> +	if (!prop)
> +		goto err_free_hborder_prop;
> +
> +	connector->underscan_vborder_property = prop;
> +
> +	drm_object_attach_property(&connector->base,
> +				   connector->underscan_mode_property,
> +				   DRM_UNDERSCAN_OFF);
> +	drm_object_attach_property(&connector->base,
> +				   connector->underscan_hborder_property, 0);
> +	drm_object_attach_property(&connector->base,
> +				   connector->underscan_vborder_property, 0);
> +
> +	return 0;
> +
> +err_free_hborder_prop:
> +	drm_property_destroy(dev, connector->underscan_hborder_property);
> +	connector->underscan_hborder_property = NULL;
> +
> +err_free_mode_prop:
> +	drm_property_destroy(dev, connector->underscan_mode_property);
> +	connector->underscan_mode_property = NULL;
> +
> +	return -ENOMEM;
> +}
> +EXPORT_SYMBOL(drm_connector_attach_underscan_properties);
> +
>  /**
>   * drm_mode_create_scaling_mode_property - create scaling mode property
>   * @dev: DRM device
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 675cc3f8cf85..46380ee6d4ee 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -372,6 +372,52 @@ struct drm_tv_connector_state {
>  	unsigned int hue;
>  };
>  
> +/**
> + * enum drm_underscan_mode - Underscan mode
> + *
> + * This enum is used to track the underscan mode.
> + *
> + * @DRM_UNDERSCAN_OFF: No underscan applied, the output image will be
unchanged
> + * @DRM_UNDERSCAN_ON: Underscan is enabled, and horizontal/vertical border
size
> + *		      are specified through the &struct_drm_underscan->hborder
> + *		      and &struct_drm_underscan->vborder fields.
> + * @DRM_UNDERSCAN_AUTO: Underscan is enabled and
&struct_drm_underscan->hborder
> + *			and &struct_drm_underscan->vborder are guessed by the
> + *			driver.
> + */
> +enum drm_underscan_mode {
> +	DRM_UNDERSCAN_OFF,
> +	DRM_UNDERSCAN_ON,
> +	DRM_UNDERSCAN_AUTO,
> +};
> +
> +/**
> + * struct drm_underscan - Underscan properties attached to a connector
state
> + *
> + * This can be used to tell the CRTC how the image should be scaled/placed
in
> + * order to cover fit in the display connected through this connector.
Most of
> + * the time used to address situations where the display borders are
hidden.
> + * Can also be used to compensate overscan done on the display side.
> + */
> +struct drm_underscan {
I'd call this drm_underscan_state, similar to how we have
drm_tv_connector_state.
> +	/**
> +	 * @mode: Underscan mode.
> +	 */
> +	enum drm_underscan_mode mode;
> +
> +	/**
> +	 * @hborder: Horizontal border. This values encodes both the left and
> +	 * right borders: left_border = right_border = hborder / 2.
> +	 */
> +	unsigned int hborder;
> +
> +	/**
> +	 * @vborder: Vertical border. This values encodes both the top and
> +	 * bottom borders: top_border = bottom_border = vborder / 2.
> +	 */
> +	unsigned int vborder;
> +};
> +
>  /**
>   * struct drm_connector_state - mutable connector state
>   * @connector: backpointer to the connector
> @@ -429,6 +475,12 @@ struct drm_connector_state {
>  	 * protection. This is most commonly used for HDCP.
>  	 */
>  	unsigned int content_protection;
> +
> +	/**
> +	 * @underscan: Underscan information. Most commonly used to adjust
> +	 * image when the display is doing overscan.
> +	 */
> +	struct drm_underscan underscan;
>  };
>  
>  /**
> @@ -892,6 +944,29 @@ struct drm_connector {
>  	 */
>  	struct drm_property_blob *tile_blob_ptr;
>  
> +	/**
> +	 * @underscan_mode_property: Optional connector underscan mode. Used by
> +	 * the driver to scale the output image and compensate an overscan done
> +	 * on the display side.
> +	 */
> +	struct drm_property *underscan_mode_property;
> +
> +	/**
> +	 * @underscan_hborder_property: Optional connector underscan horizontal
> +	 * border (expressed in pixels). Used by the driver to adjust the
> +	 * output image position and compensate an overscan done on the display
> +	 * side.
> +	 */
> +	struct drm_property *underscan_hborder_property;
> +
> +	/**
> +	 * @underscan_hborder_property: Optional connector underscan vertical
> +	 * border (expressed in pixels). Used by the driver to adjust the
> +	 * output image position and compensate an overscan done on the display
> +	 * side.
> +	 */
> +	struct drm_property *underscan_vborder_property;
Since you don't allow drivers to have a per-connector value range for
these properties these should be in drm_mode_config I think.

Yes the content_protection_property should probably have the same
treatment. Note that drm_property_blob does not derive from drm_property,
so that one is ok to be there. And the scaling property is generally
per-output.
-Daniel
> +
>  /* should we poll this connector for connects and disconnects */
>  /* hot plug detectable */
>  #define DRM_CONNECTOR_POLL_HPD (1 << 0)
> @@ -1088,6 +1163,9 @@ int drm_mode_create_dvi_i_properties(struct
drm_device *dev);
>  int drm_mode_create_tv_properties(struct drm_device *dev,
>  				  unsigned int num_modes,
>  				  const char * const modes[]);
> +int drm_connector_attach_underscan_properties(struct drm_connector
*connector,
> +					      u32 mode_mask, u64 max_hborder,
> +					      u64 max_vborder);
>  int drm_mode_create_scaling_mode_property(struct drm_device *dev);
>  int drm_connector_attach_scaling_mode_property(struct drm_connector
*connector,
>  					       u32 scaling_mode_mask);
> -- 
> 2.14.1
> 
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

On Mon, May 07, 2018 at 04:44:34PM +0200, Boris Brezillon
wrote:
> Now that the plane code takes the underscan setup into account, we can
> safely attach the underscan props to the HDMI connector.
> 
> We also take care of filling AVI infoframes correctly to expose the
> top/botton/left/right bar.
> 
> Note that these underscan props match pretty well the
> overscan_{left,right,top,bottom} properties defined in config.txt and
> parsed by the VC4 firmware.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c
b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 1a6db291d48b..17464b5981f9 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -323,6 +323,16 @@ static struct drm_connector
*vc4_hdmi_connector_init(struct drm_device *dev,
>  			   DRM_MODE_CONNECTOR_HDMIA);
>  	drm_connector_helper_add(connector,
&vc4_hdmi_connector_helper_funcs);
>  
> +	/* The hborder and vborder limit is arbitrarily set to 1024 which
> +	 * should be more than enough for real use cases. Note that the actual
> +	 * limitation comes from the display mode:
> +	 *	hborder < hdisplay && vborder < vdisplay
> +	 */
> +	drm_connector_attach_underscan_properties(connector,
We should probably sprinkle __must_check over all these :-)
-Daniel
> +						  BIT(DRM_UNDERSCAN_OFF) |
> +						  BIT(DRM_UNDERSCAN_ON),
> +						  1024, 1024);
> +
>  	connector->polled = (DRM_CONNECTOR_POLL_CONNECT |
>  			     DRM_CONNECTOR_POLL_DISCONNECT);
>  
> @@ -408,6 +418,9 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder
*encoder,
>  static void vc4_hdmi_set_avi_infoframe(struct drm_encoder *encoder)
>  {
>  	struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
> +	struct vc4_dev *vc4 = encoder->dev->dev_private;
> +	struct vc4_hdmi *hdmi = vc4->hdmi;
> +	struct drm_connector_state *cstate = hdmi->connector->state;
>  	struct drm_crtc *crtc = encoder->crtc;
>  	const struct drm_display_mode *mode =
&crtc->state->adjusted_mode;
>  	union hdmi_infoframe frame;
> @@ -426,6 +439,18 @@ static void vc4_hdmi_set_avi_infoframe(struct
drm_encoder *encoder)
>  					   vc4_encoder->rgb_range_selectable,
>  					   false);
>  
> +	if (cstate->underscan.mode == DRM_UNDERSCAN_ON) {
> +		if (cstate->underscan.hborder) {
> +			frame.avi.right_bar = cstate->underscan.hborder / 2;
> +			frame.avi.left_bar = frame.avi.right_bar;
> +		}
> +
> +		if (cstate->underscan.vborder) {
> +			frame.avi.top_bar = cstate->underscan.vborder / 2;
> +			frame.avi.bottom_bar = frame.avi.top_bar;
> +		}
> +	}
> +
>  	vc4_hdmi_write_infoframe(encoder, &frame);
>  }
>  
> -- 
> 2.14.1
> 
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Hi Boris,

I love your patch! Yet something to improve:

[auto build test ERROR on anholt/for-next]
[also build test ERROR on v4.17-rc4 next-20180507]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]

url:   
https://github.com/0day-ci/linux/commits/Boris-Brezillon/drm-connector-Provide-generic-support-for-underscan/20180508-022336
base:   https://github.com/anholt/linux for-next
config: x86_64-randconfig-x010-201818 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

   drivers/gpu//drm/drm_connector.c: In function
'drm_connector_attach_underscan_properties':
>> drivers/gpu//drm/drm_connector.c:1188:50: warning: passing argument 3
of 'drm_property_add_enum' makes integer from pointer without a cast
[-Wint-conversion]
      ret = drm_property_add_enum(prop, entry->type, entry->name);
                                                     ^~~~~
   In file included from include/drm/drm_crtc.h:42:0,
                    from include/drm/drmP.h:69,
                    from drivers/gpu//drm/drm_connector.c:23:
   include/drm/drm_property.h:263:5: note: expected 'uint64_t {aka long long
unsigned int}' but argument is of type 'const char * const'
    int drm_property_add_enum(struct drm_property *property, int index,
        ^~~~~~~~~~~~~~~~~~~~~
>> drivers/gpu//drm/drm_connector.c:1188:9: error: too few arguments to
function 'drm_property_add_enum'
      ret = drm_property_add_enum(prop, entry->type, entry->name);
            ^~~~~~~~~~~~~~~~~~~~~
   In file included from include/drm/drm_crtc.h:42:0,
                    from include/drm/drmP.h:69,
                    from drivers/gpu//drm/drm_connector.c:23:
   include/drm/drm_property.h:263:5: note: declared here
    int drm_property_add_enum(struct drm_property *property, int index,
        ^~~~~~~~~~~~~~~~~~~~~

vim +/drm_property_add_enum +1188 drivers/gpu//drm/drm_connector.c

  1141	
  1142	/**
  1143	 * drm_connector_attach_underscan_properties - attach atomic underscan
  1144	 *					       properties
  1145	 * @connector: connector to attach underscan mode properties on.
  1146	 * @mode_mask: bitmask of %DRM_UNDERSCAN_XX modes encoding the supported
  1147	 *	       underscan modes.
  1148	 * @max_hborder: maximum size of the horizontal border expressed in
pixels.
  1149	 *		 Should be > 0.
  1150	 * @max_vborder: maximum size of the vertical border expressed in pixels.
  1151	 *		 Should be > 0.
  1152	 *
  1153	 * This is used to add support for underscan to atomic drivers.
  1154	 * The underscan config will be set to &drm_connector_state.underscan
  1155	 * and can be used from &drm_connector_helper_funcs->atomic_check
for
  1156	 * validation.
  1157	 *
  1158	 * Returns:
  1159	 * Zero on success, negative errno on failure.
  1160	 */
  1161	int drm_connector_attach_underscan_properties(struct drm_connector
*connector,
  1162						      u32 mode_mask, u64 max_hborder,
  1163						      u64 max_vborder)
  1164	{
  1165		unsigned int i, nmodes = ARRAY_SIZE(drm_underscan_mode_enum_list);
  1166		struct drm_device *dev = connector->dev;
  1167		struct drm_property *prop;
  1168	
  1169		if (!max_hborder || !max_vborder)
  1170			return -EINVAL;
  1171	
  1172		if (!hweight32(mode_mask) || (mode_mask & ~GENMASK(nmodes - 1, 0)))
  1173			return -EINVAL;
  1174	
  1175		prop = drm_property_create(dev, DRM_MODE_PROP_ENUM,
"underscan",
  1176					   hweight32(mode_mask));
  1177		if (!prop)
  1178			return -ENOMEM;
  1179	
  1180		for (i = 0; i < ARRAY_SIZE(drm_underscan_mode_enum_list); i++) {
  1181			const struct drm_prop_enum_list *entry;
  1182			int ret;
  1183	
  1184			if (!(BIT(i) & mode_mask))
  1185				continue;
  1186	
  1187			entry = &drm_underscan_mode_enum_list[i];
> 1188			ret = drm_property_add_enum(prop, entry->type, entry->name);
  1189			if (ret)
  1190				goto err_free_mode_prop;
  1191		}
  1192	
  1193		connector->underscan_mode_property = prop;
  1194	
  1195		prop = drm_property_create_range(dev, 0, "underscan hborder",
0,
  1196						 max_hborder);
  1197		if (!prop)
  1198			goto err_free_mode_prop;
  1199	
  1200		connector->underscan_hborder_property = prop;
  1201	
  1202		prop = drm_property_create_range(dev, 0, "underscan vborder",
0,
  1203						 max_vborder);
  1204		if (!prop)
  1205			goto err_free_hborder_prop;
  1206	
  1207		connector->underscan_vborder_property = prop;
  1208	
  1209		drm_object_attach_property(&connector->base,
  1210					   connector->underscan_mode_property,
  1211					   DRM_UNDERSCAN_OFF);
  1212		drm_object_attach_property(&connector->base,
  1213					   connector->underscan_hborder_property, 0);
  1214		drm_object_attach_property(&connector->base,
  1215					   connector->underscan_vborder_property, 0);
  1216	
  1217		return 0;
  1218	
  1219	err_free_hborder_prop:
  1220		drm_property_destroy(dev, connector->underscan_hborder_property);
  1221		connector->underscan_hborder_property = NULL;
  1222	
  1223	err_free_mode_prop:
  1224		drm_property_destroy(dev, connector->underscan_mode_property);
  1225		connector->underscan_mode_property = NULL;
  1226	
  1227		return -ENOMEM;
  1228	}
  1229	EXPORT_SYMBOL(drm_connector_attach_underscan_properties);
  1230	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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Hi,

On Mon,  7 May 2018 16:44:31 +0200
Boris Brezillon <boris.brezillon at bootlin.com> wrote:
> Hello,
> 
> This is an attempt at providing generic support for underscan connector
> props. We already have 3 drivers defining the same underscan, underscan
> vborder and underscan hborder properties (amd, radeon and nouveau) and
> I am about to add a new one, hence my proposal to put the prop parsing
> code in the core and add ->underscan fields to drm_connector_state.
> 
> Note that I use this new infrastructure to support underscan in VC4
> (path 2 and 3) but did not patch existing drivers yet, mainly because I
> don't want to do this work before making sure I got the generic bits
> right.
Thanks everyone for your reviews. After the discussion we had on IRC
and the feedback I had on this patchset it's a bit unclear to me what
the next iteration should look like. Should I continue with the
underscan props, should I use TV margins exposed by the TV connector
state, should I create new props?

Remember that all I need is a way to define margins in order to let
the VC4 HW scaler shrink the planes and adjust their positions on the
screen.

Thanks,

Boris