linux-kernel - [PATCH] usb: dwc3: Try usb-role-switch first in dwc3_drd

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Date:   Mon, 11 Apr 2022 17:53:00 +0200
From:   Sven Peter <sven@...npeter.dev>
To:     Felipe Balbi <balbi@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Sven Peter <sven@...npeter.dev>, Yu Chen <chenyu56@...wei.com>,
        John Stultz <john.stultz@...aro.org>,
        Hector Martin <marcan@...can.st>, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] usb: dwc3: Try usb-role-switch first in dwc3_drd_init

If the PHY controller node has a "port" dwc3 tries to find an
extcon device even when "usb-role-switch" is present. This happens
because dwc3_get_extcon() sees that "port" node and then calls
extcon_find_edev_by_node() which will always return EPROBE_DEFER
in that case.

On the other hand, even if an extcon was present and dwc3_get_extcon()
was successful it would still be ignored in favor of "usb-role-switch".

Let's just first check if "usb-role-switch" is configured in the device
tree and directly use it instead and only try to look for an extcon
device otherwise.

Fixes: 8a0a13799744 ("usb: dwc3: Registering a role switch in the DRD code.")
Signed-off-by: Sven Peter <sven@...npeter.dev>
---
 drivers/usb/dwc3/drd.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index 9a22ce601504..ff40ff26275c 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -586,16 +586,15 @@ int dwc3_drd_init(struct dwc3 *dwc)
 {
 	int ret, irq;
 
+	if (ROLE_SWITCH &&
+	    device_property_read_bool(dwc->dev, "usb-role-switch"))
+		return dwc3_setup_role_switch(dwc);
+
 	dwc->edev = dwc3_get_extcon(dwc);
 	if (IS_ERR(dwc->edev))
 		return PTR_ERR(dwc->edev);
 
-	if (ROLE_SWITCH &&
-	    device_property_read_bool(dwc->dev, "usb-role-switch")) {
-		ret = dwc3_setup_role_switch(dwc);
-		if (ret < 0)
-			return ret;
-	} else if (dwc->edev) {
+	if (dwc->edev) {
 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
 					       &dwc->edev_nb);
-- 
2.25.1