usb: dwc2: Postponed gadget registration to the udc class driver

BugLink: https://bugs.launchpad.net/bugs/1885932

commit 207324a3 upstream.

During dwc2 driver probe, after gadget registration to the udc class
driver, if exist any builtin function driver it immediately bound to
dwc2 and after init host side (dwc2_hcd_init()) stucked in host mode.
Patch postpone gadget registration after host side initialization done.

Fixes: 117777b2 ("usb: dwc2: Move gadget probe function into platform code")
Reported-by: kbuild test robot <lkp@intel.com>
Tested-by: Marek Vasut <marex@denx.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Link: https://lore.kernel.org/r/f21cb38fecc72a230b86155d94c7e60c9cb66f58.1591690938.git.hminas@synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

drivers/usb/dwc2/gadget.c

@@ -3656,12 +3656,6 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
 								epnum, 0);
 	}
 
-	ret = usb_add_gadget_udc(dev, &hsotg->gadget);
-	if (ret) {
-		dwc2_hsotg_ep_free_request(&hsotg->eps_out[0]->ep,
-					   hsotg->ctrl_req);
-		return ret;
-	}
 	dwc2_hsotg_dump(hsotg);
 
 	return 0;

drivers/usb/dwc2/platform.c

@@ -452,6 +452,17 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	if (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)
 		dwc2_lowlevel_hw_disable(hsotg);
 
+#if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || \
+	IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
+	/* Postponed adding a new gadget to the udc class driver list */
+	if (hsotg->gadget_enabled) {
+		retval = usb_add_gadget_udc(hsotg->dev, &hsotg->gadget);
+		if (retval) {
+			dwc2_hsotg_remove(hsotg);
+			goto error;
+		}
+	}
+#endif /* CONFIG_USB_DWC2_PERIPHERAL || CONFIG_USB_DWC2_DUAL_ROLE */
 	return 0;
 
 error: