[PATCH v3 03/13] drm: bridge: Link encoder and bridge in core code

[Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>]

Instead of linking encoders and bridges in every driver (and getting it
wrong half of the time, as many drivers forget to set the drm_bridge
encoder pointer), do so in core code. The drm_bridge_attach() function
needs the encoder and optional previous bridge to perform that task,
update all the callers.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c   |  4 +-
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |  4 +-
 drivers/gpu/drm/bridge/dw-hdmi.c                   |  3 +-
 drivers/gpu/drm/drm_bridge.c                       | 46 ++++++++++++++++------
 drivers/gpu/drm/drm_simple_kms_helper.c            |  4 +-
 drivers/gpu/drm/exynos/exynos_dp.c                 |  5 +--
 drivers/gpu/drm/exynos/exynos_drm_dsi.c            |  6 +--
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c          |  5 +--
 drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c       |  5 +--
 drivers/gpu/drm/imx/imx-ldb.c                      |  6 +--
 drivers/gpu/drm/imx/parallel-display.c             |  4 +-
 drivers/gpu/drm/mediatek/mtk_dpi.c                 |  8 ++--
 drivers/gpu/drm/mediatek/mtk_dsi.c                 | 24 ++---------
 drivers/gpu/drm/mediatek/mtk_hdmi.c                | 11 +++---
 drivers/gpu/drm/msm/dsi/dsi_manager.c              | 17 +++++---
 drivers/gpu/drm/msm/edp/edp_bridge.c               |  2 +-
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c             |  2 +-
 drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c          |  5 +--
 drivers/gpu/drm/sti/sti_dvo.c                      |  3 +-
 drivers/gpu/drm/sti/sti_hda.c                      |  3 +-
 drivers/gpu/drm/sti/sti_hdmi.c                     |  3 +-
 drivers/gpu/drm/sun4i/sun4i_rgb.c                  | 13 +++---
 include/drm/drm_bridge.h                           |  3 +-
 23 files changed, 83 insertions(+), 103 deletions(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
index 6119b5085501..e7799b6ee829 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
@@ -230,9 +230,7 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
 	of_node_put(np);
 
 	if (bridge) {
-		output->encoder.bridge = bridge;
-		bridge->encoder = &output->encoder;
-		ret = drm_bridge_attach(dev, bridge);
+		ret = drm_bridge_attach(&output->encoder, bridge, NULL);
 		if (!ret)
 			return 0;
 	}
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 6e0447f329a2..1835f1fdad19 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1227,12 +1227,10 @@ static int analogix_dp_create_bridge(struct drm_device *drm_dev,
 
 	dp->bridge = bridge;
 
-	dp->encoder->bridge = bridge;
 	bridge->driver_private = dp;
-	bridge->encoder = dp->encoder;
 	bridge->funcs = &analogix_dp_bridge_funcs;
 
-	ret = drm_bridge_attach(drm_dev, bridge);
+	ret = drm_bridge_attach(dp->encoder, bridge, NULL);
 	if (ret) {
 		DRM_ERROR("failed to attach drm bridge\n");
 		return -EINVAL;
diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
index b71088dab268..432e0e3fff72 100644
--- a/drivers/gpu/drm/bridge/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/dw-hdmi.c
@@ -1841,13 +1841,12 @@ static int dw_hdmi_register(struct drm_device *drm, struct dw_hdmi *hdmi)
 	hdmi->bridge = bridge;
 	bridge->driver_private = hdmi;
 	bridge->funcs = &dw_hdmi_bridge_funcs;
-	ret = drm_bridge_attach(drm, bridge);
+	ret = drm_bridge_attach(encoder, bridge, NULL);
 	if (ret) {
 		DRM_ERROR("Failed to initialize bridge with drm\n");
 		return -EINVAL;
 	}
 
-	encoder->bridge = bridge;
 	hdmi->connector.polled = DRM_CONNECTOR_POLL_HPD;
 
 	drm_connector_helper_add(&hdmi->connector,
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 0ee052b7c21a..850bd6509ef1 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -26,6 +26,7 @@
 #include <linux/mutex.h>
 
 #include <drm/drm_bridge.h>
+#include <drm/drm_encoder.h>
 
 /**
  * DOC: overview
@@ -92,32 +93,53 @@ void drm_bridge_remove(struct drm_bridge *bridge)
 EXPORT_SYMBOL(drm_bridge_remove);
 
 /**
- * drm_bridge_attach - associate given bridge to our DRM device
+ * drm_bridge_attach - attach the bridge to an encoder's chain
  *
- * @dev: DRM device
- * @bridge: bridge control structure
+ * @encoder: DRM encoder
+ * @bridge: bridge to attach
+ * @previous: previous bridge in the chain (optional)
  *
- * Called by a kms driver to link one of our encoder/bridge to the given
- * bridge.
+ * Called by a kms driver to link the bridge to an encoder's chain. The previous
+ * argument specifies the previous bridge in the chain. If NULL, the bridge is
+ * linked directly at the encoder's output. Otherwise it is linked at the
+ * previous bridge's output.
  *
- * Note that setting up links between the bridge and our encoder/bridge
- * objects needs to be handled by the kms driver itself.
+ * If non-NULL the previous bridge must be already attached by a call to this
+ * function.
  *
  * RETURNS:
  * Zero on success, error code on failure
  */
-int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge)
+int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
+		      struct drm_bridge *previous)
 {
-	if (!dev || !bridge)
+	int ret;
+
+	if (!encoder || !bridge)
+		return -EINVAL;
+
+	if (previous && (!previous->dev || previous->encoder != encoder))
 		return -EINVAL;
 
 	if (bridge->dev)
 		return -EBUSY;
 
-	bridge->dev = dev;
+	bridge->dev = encoder->dev;
+	bridge->encoder = encoder;
+
+	if (bridge->funcs->attach) {
+		ret = bridge->funcs->attach(bridge);
+		if (ret < 0) {
+			bridge->dev = NULL;
+			bridge->encoder = NULL;
+			return ret;
+		}
+	}
 
-	if (bridge->funcs->attach)
-		return bridge->funcs->attach(bridge);
+	if (previous)
+		previous->next = bridge;
+	else
+		encoder->bridge = bridge;
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index 7bae08c2bf0a..ba7be6169339 100644
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -182,9 +182,7 @@ static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 					  struct drm_bridge *bridge)
 {
-	bridge->encoder = &pipe->encoder;
-	pipe->encoder.bridge = bridge;
-	return drm_bridge_attach(pipe->encoder.dev, bridge);
+	return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 }
 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 
diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c
index 528229faffe4..1ef0be338b85 100644
--- a/drivers/gpu/drm/exynos/exynos_dp.c
+++ b/drivers/gpu/drm/exynos/exynos_dp.c
@@ -99,7 +99,6 @@ static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
 				   struct drm_connector *connector)
 {
 	struct exynos_dp_device *dp = to_dp(plat_data);
-	struct drm_encoder *encoder = &dp->encoder;
 	int ret;
 
 	drm_connector_register(connector);
@@ -107,9 +106,7 @@ static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
 
 	/* Pre-empt DP connector creation if there's a bridge */
 	if (dp->ptn_bridge) {
-		bridge->next = dp->ptn_bridge;
-		dp->ptn_bridge->encoder = encoder;
-		ret = drm_bridge_attach(encoder->dev, dp->ptn_bridge);
+		ret = drm_bridge_attach(&dp->encoder, dp->ptn_bridge, bridge);
 		if (ret) {
 			DRM_ERROR("Failed to attach bridge to drm\n");
 			bridge->next = NULL;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index e07cb1fe4860..812e2ec0761d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -1718,10 +1718,8 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,
 	}
 
 	bridge = of_drm_find_bridge(dsi->bridge_node);
-	if (bridge) {
-		encoder->bridge = bridge;
-		drm_bridge_attach(drm_dev, bridge);
-	}
+	if (bridge)
+		drm_bridge_attach(encoder, bridge, NULL);
 
 	return mipi_dsi_host_register(&dsi->dsi_host);
 }
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
index e1dd75b18118..3ad76423c60d 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
@@ -167,10 +167,7 @@ static int fsl_dcu_attach_endpoint(struct fsl_dcu_drm_device *fsl_dev,
 	if (!bridge)
 		return -ENODEV;
 
-	fsl_dev->encoder.bridge = bridge;
-	bridge->encoder = &fsl_dev->encoder;
-
-	return drm_bridge_attach(fsl_dev->drm, bridge);
+	return drm_bridge_attach(&fsl_dev->encoder, bridge, NULL);
 }
 
 int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev)
diff --git a/drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c b/drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c
index 998452ad0fcb..1737e98bc10a 100644
--- a/drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c
+++ b/drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c
@@ -709,10 +709,7 @@ static int dsi_bridge_init(struct drm_device *dev, struct dw_dsi *dsi)
 	int ret;
 
 	/* associate the bridge to dsi encoder */
-	encoder->bridge = bridge;
-	bridge->encoder = encoder;
-
-	ret = drm_bridge_attach(dev, bridge);
+	ret = drm_bridge_attach(encoder, bridge, NULL);
 	if (ret) {
 		DRM_ERROR("failed to attach external bridge\n");
 		return ret;
diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c
index b300998dce7d..2fcb579f5489 100644
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@@ -461,10 +461,8 @@ static int imx_ldb_register(struct drm_device *drm,
 			 DRM_MODE_ENCODER_LVDS, NULL);
 
 	if (imx_ldb_ch->bridge) {
-		imx_ldb_ch->bridge->encoder = encoder;
-
-		imx_ldb_ch->encoder.bridge = imx_ldb_ch->bridge;
-		ret = drm_bridge_attach(drm, imx_ldb_ch->bridge);
+		ret = drm_bridge_attach(&imx_ldb_ch->encoder,
+					imx_ldb_ch->bridge, NULL);
 		if (ret) {
 			DRM_ERROR("Failed to initialize bridge with drm\n");
 			return ret;
diff --git a/drivers/gpu/drm/imx/parallel-display.c b/drivers/gpu/drm/imx/parallel-display.c
index d796ada2a47a..2d80c769f56b 100644
--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@@ -198,9 +198,7 @@ static int imx_pd_register(struct drm_device *drm,
 		drm_panel_attach(imxpd->panel, &imxpd->connector);
 
 	if (imxpd->bridge) {
-		imxpd->bridge->encoder = encoder;
-		encoder->bridge = imxpd->bridge;
-		ret = drm_bridge_attach(drm, imxpd->bridge);
+		ret = drm_bridge_attach(encoder, imxpd->bridge, NULL);
 		if (ret < 0) {
 			dev_err(imxpd->dev, "failed to attach bridge: %d\n",
 				ret);
diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 0186e500d2a5..3cced1c522fd 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -63,6 +63,7 @@ enum mtk_dpi_out_color_format {
 struct mtk_dpi {
 	struct mtk_ddp_comp ddp_comp;
 	struct drm_encoder encoder;
+	struct drm_bridge *bridge;
 	void __iomem *regs;
 	struct device *dev;
 	struct clk *engine_clk;
@@ -615,8 +616,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
 	/* Currently DPI0 is fixed to be driven by OVL1 */
 	dpi->encoder.possible_crtcs = BIT(1);
 
-	dpi->encoder.bridge->encoder = &dpi->encoder;
-	ret = drm_bridge_attach(dpi->encoder.dev, dpi->encoder.bridge);
+	ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL);
 	if (ret) {
 		dev_err(dev, "Failed to attach bridge: %d\n", ret);
 		goto err_cleanup;
@@ -713,9 +713,9 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 
 	dev_info(dev, "Found bridge node: %s\n", bridge_node->full_name);
 
-	dpi->encoder.bridge = of_drm_find_bridge(bridge_node);
+	dpi->bridge = of_drm_find_bridge(bridge_node);
 	of_node_put(bridge_node);
-	if (!dpi->encoder.bridge)
+	if (!dpi->bridge)
 		return -EPROBE_DEFER;
 
 	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 28b2044ed9f2..2ac0f1abba86 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -597,26 +597,6 @@ static const struct drm_connector_helper_funcs
 	.get_modes = mtk_dsi_connector_get_modes,
 };
 
-static int mtk_drm_attach_bridge(struct drm_bridge *bridge,
-				 struct drm_encoder *encoder)
-{
-	int ret;
-
-	if (!bridge)
-		return -ENOENT;
-
-	encoder->bridge = bridge;
-	bridge->encoder = encoder;
-	ret = drm_bridge_attach(encoder->dev, bridge);
-	if (ret) {
-		DRM_ERROR("Failed to attach bridge to drm\n");
-		encoder->bridge = NULL;
-		bridge->encoder = NULL;
-	}
-
-	return ret;
-}
-
 static int mtk_dsi_create_connector(struct drm_device *drm, struct mtk_dsi *dsi)
 {
 	int ret;
@@ -667,8 +647,10 @@ static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
 	dsi->encoder.possible_crtcs = 1;
 
 	/* If there's a bridge, attach to it and let it create the connector */
-	ret = mtk_drm_attach_bridge(dsi->bridge, &dsi->encoder);
+	ret = drm_bridge_attach(&dsi->encoder, dsi->bridge, NULL);
 	if (ret) {
+		DRM_ERROR("Failed to attach bridge to drm\n");
+
 		/* Otherwise create our own connector and attach to a panel */
 		ret = mtk_dsi_create_connector(drm, dsi);
 		if (ret)
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 71227deef21b..5ca1b0fbf937 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -149,6 +149,7 @@ struct hdmi_audio_param {
 
 struct mtk_hdmi {
 	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
 	struct drm_connector conn;
 	struct device *dev;
 	struct phy *phy;
@@ -1320,9 +1321,9 @@ static int mtk_hdmi_bridge_attach(struct drm_bridge *bridge)
 		return ret;
 	}
 
-	if (bridge->next) {
-		bridge->next->encoder = bridge->encoder;
-		ret = drm_bridge_attach(bridge->encoder->dev, bridge->next);
+	if (hdmi->next_bridge) {
+		ret = drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
+					bridge);
 		if (ret) {
 			dev_err(hdmi->dev,
 				"Failed to attach external bridge: %d\n", ret);
@@ -1505,8 +1506,8 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
 	of_node_put(ep);
 
 	if (!of_device_is_compatible(remote, "hdmi-connector")) {
-		hdmi->bridge.next = of_drm_find_bridge(remote);
-		if (!hdmi->bridge.next) {
+		hdmi->next_bridge = of_drm_find_bridge(remote);
+		if (!hdmi->next_bridge) {
 			dev_err(dev, "Waiting for external bridge\n");
 			of_node_put(remote);
 			return -EPROBE_DEFER;
diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index c8d1f19c9a6d..2bd8dad76105 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -579,6 +579,7 @@ struct drm_bridge *msm_dsi_manager_bridge_init(u8 id)
 	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
 	struct drm_bridge *bridge = NULL;
 	struct dsi_bridge *dsi_bridge;
+	struct drm_encoder *encoder;
 	int ret;
 
 	dsi_bridge = devm_kzalloc(msm_dsi->dev->dev,
@@ -590,10 +591,18 @@ struct drm_bridge *msm_dsi_manager_bridge_init(u8 id)
 
 	dsi_bridge->id = id;
 
+	/*
+	 * HACK: we may not know the external DSI bridge device's mode
+	 * flags here. We'll get to know them only when the device
+	 * attaches to the dsi host. For now, assume the bridge supports
+	 * DSI video mode
+	 */
+	encoder = msm_dsi->encoders[MSM_DSI_VIDEO_ENCODER_ID];
+
 	bridge = &dsi_bridge->base;
 	bridge->funcs = &dsi_mgr_bridge_funcs;
 
-	ret = drm_bridge_attach(msm_dsi->dev, bridge);
+	ret = drm_bridge_attach(encoder, bridge, NULL);
 	if (ret)
 		goto fail;
 
@@ -628,11 +637,7 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
 	encoder = msm_dsi->encoders[MSM_DSI_VIDEO_ENCODER_ID];
 
 	/* link the internal dsi bridge to the external bridge */
-	int_bridge->next = ext_bridge;
-	/* set the external bridge's encoder as dsi's encoder */
-	ext_bridge->encoder = encoder;
-
-	drm_bridge_attach(dev, ext_bridge);
+	drm_bridge_attach(encoder, ext_bridge, int_bridge);
 
 	/*
 	 * we need the drm_connector created by the external bridge
diff --git a/drivers/gpu/drm/msm/edp/edp_bridge.c b/drivers/gpu/drm/msm/edp/edp_bridge.c
index 2bc73f82f3f5..931a5c97cccf 100644
--- a/drivers/gpu/drm/msm/edp/edp_bridge.c
+++ b/drivers/gpu/drm/msm/edp/edp_bridge.c
@@ -106,7 +106,7 @@ struct drm_bridge *msm_edp_bridge_init(struct msm_edp *edp)
 	bridge = &edp_bridge->base;
 	bridge->funcs = &edp_bridge_funcs;
 
-	ret = drm_bridge_attach(edp->dev, bridge);
+	ret = drm_bridge_attach(edp->encoder, bridge, NULL);
 	if (ret)
 		goto fail;
 
diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
index bacbd5d8df0e..4e6d1bf27474 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
@@ -227,7 +227,7 @@ struct drm_bridge *msm_hdmi_bridge_init(struct hdmi *hdmi)
 	bridge = &hdmi_bridge->base;
 	bridge->funcs = &msm_hdmi_bridge_funcs;
 
-	ret = drm_bridge_attach(hdmi->dev, bridge);
+	ret = drm_bridge_attach(hdmi->encoder, bridge, NULL);
 	if (ret)
 		goto fail;
 
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c b/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
index a1a2c5e7822c..933a2547798e 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
@@ -124,10 +124,7 @@ int rcar_du_hdmienc_init(struct rcar_du_device *rcdu,
 	hdmienc->renc = renc;
 
 	/* Link the bridge to the encoder. */
-	bridge->encoder = encoder;
-	encoder->bridge = bridge;
-
-	ret = drm_bridge_attach(rcdu->ddev, bridge);
+	ret = drm_bridge_attach(encoder, bridge, NULL);
 	if (ret) {
 		drm_encoder_cleanup(encoder);
 		return ret;
diff --git a/drivers/gpu/drm/sti/sti_dvo.c b/drivers/gpu/drm/sti/sti_dvo.c
index e8c1ed08a9f7..411dc6ec976e 100644
--- a/drivers/gpu/drm/sti/sti_dvo.c
+++ b/drivers/gpu/drm/sti/sti_dvo.c
@@ -478,14 +478,13 @@ static int sti_dvo_bind(struct device *dev, struct device *master, void *data)
 		return err;
 	}
 
-	err = drm_bridge_attach(drm_dev, bridge);
+	err = drm_bridge_attach(encoder, bridge, NULL);
 	if (err) {
 		DRM_ERROR("Failed to attach bridge\n");
 		return err;
 	}
 
 	dvo->bridge = bridge;
-	encoder->bridge = bridge;
 	connector->encoder = encoder;
 	dvo->encoder = encoder;
 
diff --git a/drivers/gpu/drm/sti/sti_hda.c b/drivers/gpu/drm/sti/sti_hda.c
index e7c243f70870..5b1855e44f87 100644
--- a/drivers/gpu/drm/sti/sti_hda.c
+++ b/drivers/gpu/drm/sti/sti_hda.c
@@ -714,9 +714,8 @@ static int sti_hda_bind(struct device *dev, struct device *master, void *data)
 
 	bridge->driver_private = hda;
 	bridge->funcs = &sti_hda_bridge_funcs;
-	drm_bridge_attach(drm_dev, bridge);
+	drm_bridge_attach(encoder, bridge, NULL);
 
-	encoder->bridge = bridge;
 	connector->encoder = encoder;
 
 	drm_connector = (struct drm_connector *)connector;
diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index 376b0763c874..f0af1ae82ee9 100644
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -1308,9 +1308,8 @@ static int sti_hdmi_bind(struct device *dev, struct device *master, void *data)
 
 	bridge->driver_private = hdmi;
 	bridge->funcs = &sti_hdmi_bridge_funcs;
-	drm_bridge_attach(drm_dev, bridge);
+	drm_bridge_attach(encoder, bridge, NULL);
 
-	encoder->bridge = bridge;
 	connector->encoder = encoder;
 
 	drm_connector = (struct drm_connector *)connector;
diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index c3ff10f559cc..ce071c17134b 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -219,6 +219,7 @@ int sun4i_rgb_init(struct drm_device *drm)
 	struct sun4i_drv *drv = drm->dev_private;
 	struct sun4i_tcon *tcon = drv->tcon;
 	struct drm_encoder *encoder;
+	struct drm_bridge *bridge;
 	struct sun4i_rgb *rgb;
 	int ret;
 
@@ -229,8 +230,8 @@ int sun4i_rgb_init(struct drm_device *drm)
 	encoder = &rgb->encoder;
 
 	tcon->panel = sun4i_tcon_find_panel(tcon->dev->of_node);
-	encoder->bridge = sun4i_tcon_find_bridge(tcon->dev->of_node);
-	if (IS_ERR(tcon->panel) && IS_ERR(encoder->bridge)) {
+	bridge = sun4i_tcon_find_bridge(tcon->dev->of_node);
+	if (IS_ERR(tcon->panel) && IS_ERR(bridge)) {
 		dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
 		return 0;
 	}
@@ -271,16 +272,12 @@ int sun4i_rgb_init(struct drm_device *drm)
 		}
 	}
 
-	if (!IS_ERR(encoder->bridge)) {
-		encoder->bridge->encoder = &rgb->encoder;
-
-		ret = drm_bridge_attach(drm, encoder->bridge);
+	if (!IS_ERR(bridge)) {
+		ret = drm_bridge_attach(encoder, bridge, NULL);
 		if (ret) {
 			dev_err(drm->dev, "Couldn't attach our bridge\n");
 			goto err_cleanup_connector;
 		}
-	} else {
-		encoder->bridge = NULL;
 	}
 
 	return 0;
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 530a1d6e8cde..94e5ee96b3b5 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -201,7 +201,8 @@ struct drm_bridge {
 int drm_bridge_add(struct drm_bridge *bridge);
 void drm_bridge_remove(struct drm_bridge *bridge);
 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
-int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge);
+int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
+		      struct drm_bridge *previous);
 void drm_bridge_detach(struct drm_bridge *bridge);
 
 bool drm_bridge_mode_fixup(struct drm_bridge *bridge,
-- 
Regards,

Laurent Pinchart