usb: dwc3: Do not get extcon device when usb-role-switch is used

The change breaks device tree based platforms with PHY device and use
usb-role-switch instead of an extcon switch. extcon_find_edev_by_node()
will return EPROBE_DEFER if it can not find a device so probing without
an extcon device will be deferred indefinitely. Fix this by
explicitly checking for usb-role-switch.
At least the out-of-tree USB3 support on Apple silicon based platforms
using dwc3 with tipd USB Type-C and PD controller is affected by this
issue.

Fixes: d182c2e1bc92 ("usb: dwc3: Don't switch OTG -> peripheral if extcon is present")
Cc: stable@kernel.org
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20221106214804.2814-1-j@jannau.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index c0e7c76..1f348bc 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1711,6 +1711,16 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
                return extcon_get_extcon_dev(name);
 
        /*
+        * Check explicitly if "usb-role-switch" is used since
+        * extcon_find_edev_by_node() can not be used to check the absence of
+        * an extcon device. In the absence of an device it will always return
+        * EPROBE_DEFER.
+        */
+       if (IS_ENABLED(CONFIG_USB_ROLE_SWITCH) &&
+           device_property_read_bool(dev, "usb-role-switch"))
+               return NULL;
+
+       /*
         * Try to get an extcon device from the USB PHY controller's "port"
         * node. Check if it has the "port" node first, to avoid printing the
         * error message from underlying code, as it's a valid case: extcon