[PATCH 3/4] USB: ftdi_sio: clean up read completion handler

From: Johan Hovold
Date: Wed Oct 07 2009 - 14:07:51 EST


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@xxxxxxxxx>
---
drivers/usb/serial/ftdi_sio.c | 28 +---------------------------
1 files changed, 1 insertions(+), 27 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index bfb23d6..75c84d9 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 */


--
1.6.5.rc2

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