[PATCH v7 08/24] usb: gadget: udc: enable async callbacks on bind

The dwc3 driver was synced from Linux v6.16. The new ep0 code only calls
the gadget driver setup() when dwc->async_callbacks is set. In Linux the
udc core sets this flag after udc_start. U-Boot never did.

Without the flag every delegated control request, like GET_DESCRIPTOR,
returns -EINVAL and ep0 stalls. The device never enumerates, so fastboot,
DFU and UMS do not work on any dwc3 board.

Enable async callbacks after udc_start, and disable them on unbind, the
same way Linux does it.

Reported-by: Anshul Dalal <[email protected]>
Signed-off-by: Anders Roxell <[email protected]>
---
 drivers/usb/gadget/udc/udc-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index a01a7e6dc21f..79f249cbb114 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -949,6 +949,8 @@ static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
 		gadget->ops->udc_set_speed(gadget, s);
 }
 
+static inline void usb_gadget_enable_async_callbacks(struct usb_udc *udc);
+
 static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
 {
 	int ret;
@@ -968,6 +970,7 @@ static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *dri
 		driver->unbind(udc->gadget);
 		goto err1;
 	}
+	usb_gadget_enable_async_callbacks(udc);
 	udc->allow_connect = true;
 	usb_gadget_connect(udc->gadget);
 
@@ -1164,6 +1167,7 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
 			udc->driver->function);
 
 	udc->allow_connect = false;
+	usb_gadget_disable_async_callbacks(udc);
 	usb_gadget_disconnect(udc->gadget);
 	udc->driver->disconnect(udc->gadget);
 	udc->driver->unbind(udc->gadget);
-- 
2.53.0