[PATCH v2] usb: dwc3-generic: fix support without DM_REGULATOR

[Robert Marko]

Recent addition of vbus-supply support has broke platform which dont use
controllable regulators for USB.

Issue is that even withou DM_REGULATOR being enabled regulator related
functions will still build as there is a stub in regulator.h but they will
simply return -ENOSYS which will then make dwc3_generic_host_probe()
return the same error thus breaking probe.

So, check whether return code is -ENOSYS before erroring out.

Fixes: de451d5d5b6f ("usb: dwc3-generic: support external vbus regulator")
Signed-off-by: Robert Marko <robert.marko at sartura.hr>
---
Changes in v2:
* Drop #ifdefs and check for -ENOSYS that regulator stub returns

 drivers/usb/dwc3/dwc3-generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index 7a00529a2a..df0b0b8c02 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -248,7 +248,7 @@ static int dwc3_generic_host_probe(struct udevice *dev)
 
 	/* Only returns an error if regulator is valid and failed to enable due to a driver issue */
 	rc = regulator_set_enable_if_allowed(priv->vbus_supply, true);
-	if (rc)
+	if (rc && rc != -ENOSYS)
 		return rc;
 
 	hccr = (struct xhci_hccr *)priv->gen_priv.base;
-- 
2.44.0