USB: ftdi_sio: clean up read completion handler

Remove superfluous error checks in completion handler:

 - No need to check private data and urb pointers as we check urb-status
   before dereferencing priv (which is not freed until urb has been killed
   on close).
 - No need to check tty as it is checked again when processing.
 - No need to check urb->number_of_packets on bulk urb.

Note that both private data and tty are checked again before processing
(possibly from work queue which also is cancelled on close).

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1 insertions, 27 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index bfb23d64bc6a..75c84d9b080d 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2008,39 +2008,14 @@ static int ftdi_chars_in_buffer(struct tty_struct *tty)
 static void ftdi_read_bulk_callback(struct urb *urb)
 {
         struct usb_serial_port *port = urb->context;
-        struct tty_struct *tty;
         struct ftdi_private *priv;
         int status = urb->status;
 
-        if (urb->number_of_packets > 0) {
-                dev_err(&port->dev, "%s transfer_buffer_length %d "
-                        "actual_length %d number of packets %d\n", __func__,
-                        urb->transfer_buffer_length,
-                        urb->actual_length, urb->number_of_packets);
-                dev_err(&port->dev, "%s transfer_flags %x\n", __func__,
-                        urb->transfer_flags);
-        }
-
         dbg("%s - port %d", __func__, port->number);
 
         if (port->port.count <= 0)
                 return;
 
-        tty = tty_port_tty_get(&port->port);
-        if (!tty) {
-                dbg("%s - bad tty pointer - exiting", __func__);
-                return;
-        }
-
-        priv = usb_get_serial_port_data(port);
-        if (!priv) {
-                dbg("%s - bad port private data pointer - exiting", __func__);
-                goto out;
-        }
-
-        if (urb != port->read_urb)
-                dev_err(&port->dev, "%s - Not my urb!\n", __func__);
-
         if (status) {
                 /* This will happen at close every time so it is a dbg not an
                    err */
@@ -2048,9 +2023,8 @@ static void ftdi_read_bulk_callback(struct urb *urb)
                 goto out;
         }
 
+        priv = usb_get_serial_port_data(port);
         ftdi_process_read(&priv->rx_work.work);
-out:
-        tty_kref_put(tty);
 } /* ftdi_read_bulk_callback */