[PATCH] drm/bridge: display-connector: fix i2c adapter leak on probe failure

[Johan Hovold <johan@kernel.org>]

Make sure to drop the i2c adapter device and module references on failed
regulator and enable gpio lookup (and regulator enable) during probe
(e.g. on probe deferral).

Note that of_get_i2c_adapter_by_node() does not return error pointers,
but i2c_put_adapter() can handle a NULL argument so the error pointer
check at remove works even if it is misleading.

Fixes: 2e2bf3a5584d ("drm/bridge: display-connector: add DP support")
Fixes: 6de79dd3a920 ("drm/bridge: display-connector: add ddc-en gpio support")
Fixes: 6eb6b6f0a012 ("drm/bridge: display-connector: handle hdmi-pwr supply")
Cc: stable@vger.kernel.org	# 5.12
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Dmitry Baryshkov <lumag@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpu/drm/bridge/display-connector.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
index 16c0631adeb1..c38de5518211 100644
--- a/drivers/gpu/drm/bridge/display-connector.c
+++ b/drivers/gpu/drm/bridge/display-connector.c
@@ -208,6 +208,13 @@ static int display_connector_get_supply(struct platform_device *pdev,
 	return PTR_ERR_OR_ZERO(conn->supply);
 }
 
+static void display_connector_put_ddc(void *_ddc)
+{
+	struct i2c_adapter *ddc = _ddc;
+
+	i2c_put_adapter(ddc);
+}
+
 static int display_connector_probe(struct platform_device *pdev)
 {
 	struct display_connector *conn;
@@ -328,6 +335,12 @@ static int display_connector_probe(struct platform_device *pdev)
 			of_node_put(phandle);
 			if (!conn->bridge.ddc)
 				return -EPROBE_DEFER;
+
+			ret = devm_add_action_or_reset(&pdev->dev,
+						       display_connector_put_ddc,
+						       conn->bridge.ddc);
+			if (ret)
+				return ret;
 		} else {
 			dev_dbg(&pdev->dev,
 				"No I2C bus specified, disabling EDID readout\n");
@@ -403,9 +416,6 @@ static void display_connector_remove(struct platform_device *pdev)
 		regulator_disable(conn->supply);
 
 	drm_bridge_remove(&conn->bridge);
-
-	if (!IS_ERR(conn->bridge.ddc))
-		i2c_put_adapter(conn->bridge.ddc);
 }
 
 static const struct of_device_id display_connector_match[] = {
-- 
2.54.0