usb: dwc3: gadget: Fix dep->interval for fullspeed interrupt

The dep->interval captures the number of frames/microframes per interval
from bInterval. Fullspeed interrupt endpoint bInterval is the number of
frames per interval and not 2^(bInterval - 1). So fix it here. This
change is only for debugging purpose and should not affect the interrupt
endpoint operation.

Fixes: 72246da4 ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/1263b563dedc4ab8b0fb854fba06ce4bc56bd495.1612820995.git.Thinh.Nguyen@synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/gadget.c

@@ -615,8 +615,13 @@ static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)
 		if (dwc->gadget->speed == USB_SPEED_FULL)
 			bInterval_m1 = 0;
 
+		if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT &&
+		    dwc->gadget->speed == USB_SPEED_FULL)
+			dep->interval = desc->bInterval;
+		else
+			dep->interval = 1 << (desc->bInterval - 1);
+
 		params.param1 |= DWC3_DEPCFG_BINTERVAL_M1(bInterval_m1);
-		dep->interval = 1 << (desc->bInterval - 1);
 	}
 
 	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETEPCONFIG, &params);