[PATCH v4] drm/ingenic: fix bridge allocation

Bridge allocation API has changed and ingenic/drm was broken
leading to

[   54.997593] dw-hdmi-ingenic 10180000.hdmi: Detected HDMI \X controller v1.31a with HDCP (DWC HDMI 3D TX PHY)
[   55.491338] dw-hdmi-ingenic 10180000.hdmi: registered DesignWare HDMI I2C bus driver
[   55.899132] [drm] DRM bridge corrupted or not allocated by devm_drm_bridge_alloc()
[   55.904136] ------------[ cut here ]------------
[   55.908753] WARNING: lib/refcount.c:25 at drm_bridge_get+0x58/0x6c [drm], CPU#0: kworker/u4:2/36
[   55.917538] refcount_t: addition on 0; use-after-free.
...
[   56.354928] [<c04898b8>] drm_bridge_attach+0x80/0x208 [drm]
...

Fixes: 9347f2fbb0183b0 ("drm/bridge: add warning for bridges using neither devm_drm_bridge_alloc() nor drm_bridge_add()")
Tested-by: Waldemar Brodkorb <[email protected]> (on CI20 with HDMI)
Signed-off-by: H. Nikolaus Schaller <[email protected]>
Cc: Waldemar Brodkorb <[email protected]>
Cc: [email protected]
---

Notes:
    v4: remove setting interlaced mode (would be new feature and not a fix) as suggested by [email protected]
    
    v3: fixed a malformed diff in v2
    
    v2: removed ib->bridge->ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT as suggested by Sashiko-reviews
        https://sashiko.dev/#/patchset/400ba2fe0d4f76484e929d2efaa32f67a940163a.1787477392.git.hns@goldelico.com?part=1

 drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
index 42c86f195c66b3..f3c6c823314688 100644
--- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
@@ -122,7 +122,7 @@ struct ingenic_drm {
 
 struct ingenic_drm_bridge {
 	struct drm_encoder encoder;
-	struct drm_bridge bridge, *next_bridge;
+	struct drm_bridge *bridge, *next_bridge;
 
 	struct drm_bus_cfg bus_cfg;
 };
@@ -802,7 +802,7 @@ static int ingenic_drm_bridge_attach(struct drm_bridge *bridge,
 	struct ingenic_drm_bridge *ib = to_ingenic_drm_bridge(encoder);
 
 	return drm_bridge_attach(encoder, ib->next_bridge,
-				 &ib->bridge, flags);
+				 bridge, flags);
 }
 
 static int ingenic_drm_bridge_atomic_check(struct drm_bridge *bridge,
@@ -1314,10 +1314,23 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
 
 		drm_encoder_helper_add(encoder, &ingenic_drm_encoder_helper_funcs);
 
-		ib->bridge.funcs = &ingenic_drm_bridge_funcs;
+		ib->bridge = devm_drm_bridge_alloc(priv->dev, struct drm_bridge,
+						   base, &ingenic_drm_bridge_funcs);
+		if (IS_ERR(ib->bridge)) {
+			ret = PTR_ERR(ib->bridge);
+			goto err_drvdata;
+		}
+
+		ib->bridge->of_node = priv->dev->of_node;
 		ib->next_bridge = bridge;
 
-		ret = drm_bridge_attach(encoder, &ib->bridge, NULL,
+		ret = devm_drm_bridge_add(priv->dev, ib->bridge);
+		if (ret) {
+			dev_err(dev, "Failed to register DRM bridge: %d\n", ret);
+			goto err_drvdata;
+		}
+
+		ret = drm_bridge_attach(encoder, ib->bridge, NULL,
 					DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 		if (ret) {
 			dev_err(dev, "Unable to attach bridge\n");
-- 
2.55.0