[PATCH v2 2/2] usb: typec: mux: avoid duplicated mux switches

[Sebastian Reichel]

Some devices use combo PHYs (i.e. USB3 + DisplayPort), which also
handle the lane muxing. These PHYs are referenced twice from
the USB-C connector (USB super-speed lines and SBU/AUX lines)
resulting in the mux being configured twice. Avoid this by
dropping duplicates.

Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
 drivers/usb/typec/mux.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
index 9b908c46bd7d..db5e4a4c0a99 100644
--- a/drivers/usb/typec/mux.c
+++ b/drivers/usb/typec/mux.c
@@ -275,7 +275,9 @@ static int mux_fwnode_match(struct device *dev, const void *fwnode)
 static void *typec_mux_match(const struct fwnode_handle *fwnode,
 			     const char *id, void *data)
 {
+	struct typec_mux_dev **mux_devs = data;
 	struct device *dev;
+	int i;
 
 	/*
 	 * Device graph (OF graph) does not give any means to identify the
@@ -291,6 +293,14 @@ static void *typec_mux_match(const struct fwnode_handle *fwnode,
 	dev = class_find_device(&typec_mux_class, NULL, fwnode,
 				mux_fwnode_match);
 
+	/* Skip duplicates */
+	for (i = 0; i < TYPEC_MUX_MAX_DEVS; i++)
+		if (to_typec_mux_dev(dev) == mux_devs[i]) {
+			put_device(dev);
+			return NULL;
+		}
+
+
 	return dev ? to_typec_mux_dev(dev) : ERR_PTR(-EPROBE_DEFER);
 }
 
@@ -316,7 +326,8 @@ struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode)
 		return ERR_PTR(-ENOMEM);
 
 	count = fwnode_connection_find_matches(fwnode, "mode-switch",
-					       NULL, typec_mux_match,
+					       (void **)mux_devs,
+					       typec_mux_match,
 					       (void **)mux_devs,
 					       ARRAY_SIZE(mux_devs));
 	if (count <= 0) {

-- 
2.51.0