windows/serialInterface: Corrected the timeouts configuration as the …

…one copied from from BMDA was all kinds of wrong

src/windows/serialInterface.cxx

@@ -214,11 +214,15 @@ serialInterface_t::serialInterface_t(const usbDevice_t &usbDevice) : device
 	}
 
 	COMMTIMEOUTS timeouts{};
-	timeouts.ReadIntervalTimeout = 10;
-	timeouts.ReadTotalTimeoutConstant = 10;
-	timeouts.ReadTotalTimeoutMultiplier = 10;
-	timeouts.WriteTotalTimeoutConstant = 10;
-	timeouts.WriteTotalTimeoutMultiplier = 10;
+	// Turn off read timeouts so that ReadFill() instantly returns even if there's no data waiting
+	// (we implement our own mechanism below for that case as we only want to wait if we get no data)
+	timeouts.ReadIntervalTimeout = MAXDWORD;
+	timeouts.ReadTotalTimeoutConstant = 0;
+	timeouts.ReadTotalTimeoutMultiplier = 0;
+	// Configure an exactly 100ms write timeout - we want this triggering to be fatal as something
+	// has gone very wrong if we ever hit this.
+	timeouts.WriteTotalTimeoutConstant = 100;
+	timeouts.WriteTotalTimeoutMultiplier = 0;
 	if (!SetCommTimeouts(device, &timeouts))
 		handleDeviceError("set communications timeouts for device"sv);