usb: typec: mux: avoid duplicated mux switches

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@collabora.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260223-typec-mux-duplication-fix-v2-2-0402fefc222e@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
index 9b908c46bd7df9fe78ac0a5eeeb9b03d6587ba80..db5e4a4c0a99699c4c0f715d281cdc85f1e68c77 100644 (file)
--- 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) {