[v1] usb: dwc3: drd: Defer probe if extcon device is not found

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

In case the "linux,extcon-name" property is defined but device itself
is not ready, defer the probe.

Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---

This is a missed part of the v2 [1] of the commit 268784ba14a7

    ("usb: dwc3: drd: Add support for DR detection through extcon")

which seems to be v1 mistakenly applied.

Greg, it would be good to have this appended to v5.0 release,
if it's not too late.

[1]: https://patchwork.kernel.org/patch/10684311/

 drivers/usb/dwc3/drd.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index 869725d15c74..726100d1ac0d 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -457,8 +457,13 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
 	 * This device property is for kernel internal use only and
 	 * is expected to be set by the glue code.
 	 */
-	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0)
-		return extcon_get_extcon_dev(name);
+	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0) {
+		edev = extcon_get_extcon_dev(name);
+		if (!edev)
+			return ERR_PTR(-EPROBE_DEFER);
+
+		return edev;
+	}
 
 	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
 	np_conn = of_graph_get_remote_node(np_phy, -1, -1);