driver: usb_dc_sam_usbhs: Restore EP0 after detach

SAM V71 Xplained Ultra failed to re-enumerate on the bus after device
detach-attach sequence. The device was recognized by the host, but it
was not responding to control transfers, i.e. it was not acknowledging
SETUP data. Make device acknowledge SETUP data by reconfiguring EP0
when necessary.

Signed-off-by: Tomasz Moń <[email protected]>

Author: tmon-nordic

drivers/usb/device/usb_dc_sam_usbhs.c

@@ -244,6 +244,16 @@ static void usb_dc_isr(void)
 		/* Acknowledge the interrupt */
 		USBHS->USBHS_DEVICR = USBHS_DEVICR_EORSTC;
 
+		if (!usb_dc_ep_is_configured(0) && dev_data.ep_data[0].mps) {
+			/* Restore EP0 configuration to previously set mps */
+			struct usb_dc_ep_cfg_data cfg = {
+				.ep_addr = 0,
+				.ep_mps = dev_data.ep_data[0].mps,
+				.ep_type = USB_DC_EP_CONTROL,
+			};
+			usb_dc_ep_configure(&cfg);
+			usb_dc_ep_enable(0);
+		}
 		if (usb_dc_ep_is_enabled(0)) {
 			/* The device clears some of the configuration of EP0
 			 * when it receives the EORST.  Re-enable interrupts.