Re:[RFC PATCH v2 1/3] drm/bridge: cadence: cdns-mhdp8546-core: Remove legacy support for connector initialisation in bridge

["Andy Yan" <andyshrk@163.com>]

Hello Javesh,

At 2025-05-21 15:32:35, "Jayesh Choudhary" <j-choudhary@ti.com> wrote:
>Now that we have DBANC framework, remove the connector initialisation code
>as that piece of code is not called if DRM_BRIDGE_ATTACH_NO_CONNECTOR flag
>is used. Only TI K3 platforms consume this driver and tidss (their display
>controller) has this flag set. So this legacy support can be dropped.
>
>Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
>---
> .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 186 +++---------------
> 1 file changed, 25 insertions(+), 161 deletions(-)
>
>diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>index b431e7efd1f0..66bd916c2fe9 100644
>--- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>@@ -1444,56 +1444,6 @@ static const struct drm_edid *cdns_mhdp_edid_read(struct cdns_mhdp_device *mhdp,
> 	return drm_edid_read_custom(connector, cdns_mhdp_get_edid_block, mhdp);
> }
> 
>-static int cdns_mhdp_get_modes(struct drm_connector *connector)
>-{
>-	struct cdns_mhdp_device *mhdp = connector_to_mhdp(connector);
>-	const struct drm_edid *drm_edid;
>-	int num_modes;
>-
>-	if (!mhdp->plugged)
>-		return 0;
>-
>-	drm_edid = cdns_mhdp_edid_read(mhdp, connector);
>-
>-	drm_edid_connector_update(connector, drm_edid);
>-
>-	if (!drm_edid) {
>-		dev_err(mhdp->dev, "Failed to read EDID\n");
>-		return 0;
>-	}
>-
>-	num_modes = drm_edid_connector_add_modes(connector);
>-	drm_edid_free(drm_edid);
>-
>-	/*
>-	 * HACK: Warn about unsupported display formats until we deal
>-	 *       with them correctly.
>-	 */
>-	if (connector->display_info.color_formats &&
>-	    !(connector->display_info.color_formats &
>-	      mhdp->display_fmt.color_format))
>-		dev_warn(mhdp->dev,
>-			 "%s: No supported color_format found (0x%08x)\n",
>-			__func__, connector->display_info.color_formats);
>-
>-	if (connector->display_info.bpc &&
>-	    connector->display_info.bpc < mhdp->display_fmt.bpc)
>-		dev_warn(mhdp->dev, "%s: Display bpc only %d < %d\n",
>-			 __func__, connector->display_info.bpc,
>-			 mhdp->display_fmt.bpc);
>-
>-	return num_modes;
>-}
>-
>-static int cdns_mhdp_connector_detect(struct drm_connector *conn,
>-				      struct drm_modeset_acquire_ctx *ctx,
>-				      bool force)
>-{
>-	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
>-
>-	return cdns_mhdp_detect(mhdp);
>-}
>-
> static u32 cdns_mhdp_get_bpp(struct cdns_mhdp_display_fmt *fmt)
> {
> 	u32 bpp;
>@@ -1547,114 +1497,6 @@ bool cdns_mhdp_bandwidth_ok(struct cdns_mhdp_device *mhdp,
> 	return true;
> }
> 
>-static
>-enum drm_mode_status cdns_mhdp_mode_valid(struct drm_connector *conn,
>-					  const struct drm_display_mode *mode)
>-{
>-	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
>-
>-	mutex_lock(&mhdp->link_mutex);
>-
>-	if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
>-				    mhdp->link.rate)) {
>-		mutex_unlock(&mhdp->link_mutex);
>-		return MODE_CLOCK_HIGH;
>-	}
>-
>-	mutex_unlock(&mhdp->link_mutex);
>-	return MODE_OK;
>-}
>-
>-static int cdns_mhdp_connector_atomic_check(struct drm_connector *conn,
>-					    struct drm_atomic_state *state)
>-{
>-	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
>-	struct drm_connector_state *old_state, *new_state;
>-	struct drm_crtc_state *crtc_state;
>-	u64 old_cp, new_cp;
>-
>-	if (!mhdp->hdcp_supported)
>-		return 0;
>-
>-	old_state = drm_atomic_get_old_connector_state(state, conn);
>-	new_state = drm_atomic_get_new_connector_state(state, conn);
>-	old_cp = old_state->content_protection;
>-	new_cp = new_state->content_protection;
>-
>-	if (old_state->hdcp_content_type != new_state->hdcp_content_type &&
>-	    new_cp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
>-		new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
>-		goto mode_changed;
>-	}
>-
>-	if (!new_state->crtc) {
>-		if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
>-			new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
>-		return 0;
>-	}
>-
>-	if (old_cp == new_cp ||
>-	    (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
>-	     new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED))
>-		return 0;
>-
>-mode_changed:
>-	crtc_state = drm_atomic_get_new_crtc_state(state, new_state->crtc);
>-	crtc_state->mode_changed = true;
>-
>-	return 0;
>-}
>-
>-static const struct drm_connector_helper_funcs cdns_mhdp_conn_helper_funcs = {
>-	.detect_ctx = cdns_mhdp_connector_detect,
>-	.get_modes = cdns_mhdp_get_modes,
>-	.mode_valid = cdns_mhdp_mode_valid,
>-	.atomic_check = cdns_mhdp_connector_atomic_check,
>-};
>-
>-static const struct drm_connector_funcs cdns_mhdp_conn_funcs = {
>-	.fill_modes = drm_helper_probe_single_connector_modes,
>-	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>-	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>-	.reset = drm_atomic_helper_connector_reset,
>-	.destroy = drm_connector_cleanup,
>-};
>-
>-static int cdns_mhdp_connector_init(struct cdns_mhdp_device *mhdp)
>-{
>-	u32 bus_format = MEDIA_BUS_FMT_RGB121212_1X36;
>-	struct drm_connector *conn = &mhdp->connector;
>-	struct drm_bridge *bridge = &mhdp->bridge;
>-	int ret;
>-
>-	conn->polled = DRM_CONNECTOR_POLL_HPD;
>-
>-	ret = drm_connector_init(bridge->dev, conn, &cdns_mhdp_conn_funcs,
>-				 DRM_MODE_CONNECTOR_DisplayPort);
>-	if (ret) {
>-		dev_err(mhdp->dev, "Failed to initialize connector with drm\n");
>-		return ret;
>-	}
>-
>-	drm_connector_helper_add(conn, &cdns_mhdp_conn_helper_funcs);
>-
>-	ret = drm_display_info_set_bus_formats(&conn->display_info,
>-					       &bus_format, 1);
>-	if (ret)
>-		return ret;
>-
>-	ret = drm_connector_attach_encoder(conn, bridge->encoder);
>-	if (ret) {
>-		dev_err(mhdp->dev, "Failed to attach connector to encoder\n");
>-		return ret;
>-	}
>-
>-	if (mhdp->hdcp_supported)
>-		ret = drm_connector_attach_content_protection_property(conn, true);
>-
>-	return ret;
>-}
>-
> static int cdns_mhdp_attach(struct drm_bridge *bridge,
> 			    struct drm_encoder *encoder,
> 			    enum drm_bridge_attach_flags flags)
>@@ -1671,9 +1513,11 @@ static int cdns_mhdp_attach(struct drm_bridge *bridge,
> 		return ret;
> 
> 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
>-		ret = cdns_mhdp_connector_init(mhdp);
>-		if (ret)
>-			goto aux_unregister;
>+		ret = -EINVAL;
>+		dev_err(mhdp->dev,
>+			"Connector initialisation not supported in bridge_attach %d\n",
>+			ret);
>+		goto aux_unregister;
> 	}
> 
> 	spin_lock(&mhdp->start_lock);
>@@ -2158,6 +2002,25 @@ static const struct drm_edid *cdns_mhdp_bridge_edid_read(struct drm_bridge *brid
> 	return cdns_mhdp_edid_read(mhdp, connector);
> }
> 
>+static enum drm_mode_status
>+cdns_mhdp_bridge_mode_valid(struct drm_bridge *bridge,
>+			    const struct drm_display_info *info,
>+			    const struct drm_display_mode *mode)
>+{
>+	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
>+
>+	mutex_lock(&mhdp->link_mutex);
>+
>+	if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
>+				    mhdp->link.rate)) {
>+		mutex_unlock(&mhdp->link_mutex);
>+		return MODE_CLOCK_HIGH;
>+	}
>+
>+	mutex_unlock(&mhdp->link_mutex);
>+	return MODE_OK;
>+}
>+
> static const struct drm_bridge_funcs cdns_mhdp_bridge_funcs = {
> 	.atomic_enable = cdns_mhdp_atomic_enable,
> 	.atomic_disable = cdns_mhdp_atomic_disable,
>@@ -2172,6 +2035,7 @@ static const struct drm_bridge_funcs cdns_mhdp_bridge_funcs = {
> 	.edid_read = cdns_mhdp_bridge_edid_read,
> 	.hpd_enable = cdns_mhdp_bridge_hpd_enable,
> 	.hpd_disable = cdns_mhdp_bridge_hpd_disable,
>+	.mode_valid = cdns_mhdp_bridge_mode_valid,

Do we need the detect hook for bridge after cdns_mhdp_connector_detect removed ?



> };
> 
> static bool cdns_mhdp_detect_hpd(struct cdns_mhdp_device *mhdp, bool *hpd_pulse)
>-- 
>2.34.1