[PATCH 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 | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
index db35b7398343..6a394326f236 100644
--- a/drivers/usb/typec/mux.c
+++ b/drivers/usb/typec/mux.c
@@ -309,9 +309,9 @@ struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode)
 {
 	struct typec_mux_dev *mux_devs[TYPEC_MUX_MAX_DEVS];
 	struct typec_mux *mux;
+	int i, j, k;
 	int count;
 	int err;
-	int i;
 
 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 	if (!mux)
@@ -333,6 +333,18 @@ struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode)
 		}
 	}
 
+	/* eliminate duplicates */
+	for (i = 0; i < count; i++) {
+		for (j = i + 1; j < count; j++) {
+			if (mux_devs[j] == mux_devs[i]) {
+				put_device(&mux_devs[j]->dev);
+				for (k = j; k < count; k++)
+					mux_devs[k] = mux_devs[k+1];
+				count--;
+			}
+		}
+	}
+
 	for (i = 0; i < count; i++) {
 		WARN_ON(!try_module_get(mux_devs[i]->dev.parent->driver->owner));
 		mux->mux_devs[i] = mux_devs[i];

-- 
2.51.0