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-rw-r--r--drivers/usb/serial/ftdi_sio.c18
1 files changed, 11 insertions, 7 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index e4d7fbd7e4e..242b5776648 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1789,20 +1789,24 @@ static int ftdi_8u2232c_probe(struct usb_serial *serial)
}
/*
- * First and second port on STMCLiteadaptors is reserved for JTAG interface
- * and the forth port for pio
+ * First two ports on JTAG adaptors using an FT4232 such as STMicroelectronics's
+ * ST Micro Connect Lite are reserved for JTAG or other non-UART interfaces and
+ * can be accessed from userspace.
+ * The next two ports are enabled as UARTs by default, where port 2 is
+ * a conventional RS-232 UART.
*/
static int ftdi_stmclite_probe(struct usb_serial *serial)
{
struct usb_device *udev = serial->dev;
struct usb_interface *interface = serial->interface;
- if (interface == udev->actconfig->interface[2])
- return 0;
-
- dev_info(&udev->dev, "Ignoring serial port reserved for JTAG\n");
+ if (interface == udev->actconfig->interface[0] ||
+ interface == udev->actconfig->interface[1]) {
+ dev_info(&udev->dev, "Ignoring serial port reserved for JTAG\n");
+ return -ENODEV;
+ }
- return -ENODEV;
+ return 0;
}
/*