[PATCH v2 1/2] drm: rcar-du: mipi-dsi: Support bridge probe ordering

[Kieran Bingham]

The bridge probe ordering for DSI devices has been clarified and further
documented in

To support connecting with the SN65DSI86 device after commit c3b75d4734cb
("drm/bridge: sn65dsi86: Register and attach our DSI device at probe"),
update to the new probe ordering to remove a perpetual -EPROBE_DEFER
loop between the two devices.

Signed-off-by: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com>

---
v2
- Remove now unused panel variable from rcar_mipi_dsi_probe()

 drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c | 49 +++++++++++++------------
 1 file changed, 26 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c 
b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
index 50e922328fed..0a9f197ef62c 100644
--- a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
+++ b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
@@ -637,6 +637,8 @@ static int rcar_mipi_dsi_host_attach(struct mipi_dsi_host 
*host,
                                        struct mipi_dsi_device *device)
 {
        struct rcar_mipi_dsi *dsi = host_to_rcar_mipi_dsi(host);
+       struct drm_panel *panel;
+       int ret;
 
        if (device->lanes > dsi->num_data_lanes)
                return -EINVAL;
@@ -644,12 +646,36 @@ static int rcar_mipi_dsi_host_attach(struct mipi_dsi_host 
*host,
        dsi->lanes = device->lanes;
        dsi->format = device->format;
 
+       ret = drm_of_find_panel_or_bridge(dsi->dev->of_node, 1, 0, &panel,
+                                         &dsi->next_bridge);
+       if (ret) {
+               dev_err_probe(dsi->dev, ret, "could not find next bridge\n");
+               return ret;
+       }
+
+       if (!dsi->next_bridge) {
+               dsi->next_bridge = devm_drm_panel_bridge_add(dsi->dev, panel);
+               if (IS_ERR(dsi->next_bridge)) {
+                       dev_err(dsi->dev, "failed to create panel bridge\n");
+                       return PTR_ERR(dsi->next_bridge);
+               }
+       }
+
+       /* Initialize the DRM bridge. */
+       dsi->bridge.funcs = &rcar_mipi_dsi_bridge_ops;
+       dsi->bridge.of_node = dsi->dev->of_node;
+       drm_bridge_add(&dsi->bridge);
+
        return 0;
 }
 
 static int rcar_mipi_dsi_host_detach(struct mipi_dsi_host *host,
                                        struct mipi_dsi_device *device)
 {
+       struct rcar_mipi_dsi *dsi = host_to_rcar_mipi_dsi(host);
+
+       drm_bridge_remove(&dsi->bridge);
+
        return 0;
 }
 
@@ -731,7 +757,6 @@ static int rcar_mipi_dsi_get_clocks(struct rcar_mipi_dsi 
*dsi)
 static int rcar_mipi_dsi_probe(struct platform_device *pdev)
 {
        struct rcar_mipi_dsi *dsi;
-       struct drm_panel *panel;
        struct resource *mem;
        int ret;
 
@@ -764,21 +789,6 @@ static int rcar_mipi_dsi_probe(struct platform_device 
*pdev)
                return PTR_ERR(dsi->rstc);
        }
 
-       ret = drm_of_find_panel_or_bridge(dsi->dev->of_node, 1, 0, &panel,
-                                         &dsi->next_bridge);
-       if (ret) {
-               dev_err_probe(dsi->dev, ret, "could not find next bridge\n");
-               return ret;
-       }
-
-       if (!dsi->next_bridge) {
-               dsi->next_bridge = devm_drm_panel_bridge_add(dsi->dev, panel);
-               if (IS_ERR(dsi->next_bridge)) {
-                       dev_err(dsi->dev, "failed to create panel bridge\n");
-                       return PTR_ERR(dsi->next_bridge);
-               }
-       }
-
        /* Initialize the DSI host. */
        dsi->host.dev = dsi->dev;
        dsi->host.ops = &rcar_mipi_dsi_host_ops;
@@ -786,11 +796,6 @@ static int rcar_mipi_dsi_probe(struct platform_device 
*pdev)
        if (ret < 0)
                return ret;
 
-       /* Initialize the DRM bridge. */
-       dsi->bridge.funcs = &rcar_mipi_dsi_bridge_ops;
-       dsi->bridge.of_node = dsi->dev->of_node;
-       drm_bridge_add(&dsi->bridge);
-
        return 0;
 }
 
@@ -798,8 +803,6 @@ static int rcar_mipi_dsi_remove(struct platform_device 
*pdev)
 {
        struct rcar_mipi_dsi *dsi = platform_get_drvdata(pdev);
 
-       drm_bridge_remove(&dsi->bridge);
-
        mipi_dsi_host_unregister(&dsi->host);
 
        return 0;
-- 
2.30.2