On Sun, 21 Mar 2010, James Maki wrote:
> All unsuccessful (non-zero status) URBs were being dropped. After N_IN_URBs are
> dropped you will no longer be able to receive data.
>
> This patch resubmits unsuccessful URBs unless the status indicates that it should
> be terminated. The statuses that indicate the URB should be terminated was
> gathered from other similar drivers.
>
> Please CC James Maki <jamescmaki@xxxxxxxxx>
You don't need this line in the Changelog, because your name and email
address will automatically show up as the author of the patch.
> Signed-off-by: James Maki <jamescmaki@xxxxxxxxx>
> ---
> drivers/usb/serial/option.c | 51 ++++++++++++++++++++++++++----------------
> 1 files changed, 31 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
> index 950cb31..f2f6a60 100644
> --- a/drivers/usb/serial/option.c
> +++ b/drivers/usb/serial/option.c
> @@ -1008,31 +1008,42 @@ static void option_indat_callback(struct urb *urb)
> dbg("%s: %p", __func__, urb);
>
> endpoint = usb_pipeendpoint(urb->pipe);
> - port = urb->context;
> -
> - if (status) {
> + port = urb->context;
> +
> + switch (status) {
> + case 0:
> + /* success */
> + break;
> + case -ECONNRESET:
> + case -ENOENT:
> + case -ESHUTDOWN:
> + /* this urb is terminated, clean up */
> + dbg("%s: urb shutting down with status: %d on endpoint %02x.",
> + __func__, status, endpoint);
> + return;
> + default:
> dbg("%s: nonzero status: %d on endpoint %02x.",
> __func__, status, endpoint);
> - } else {
> + goto exit;
You might want to omit this goto. In principle a failed URB can still
contain some valid data.
> + }
> +
> + if (urb->actual_length) {
> tty = tty_port_tty_get(&port->port);
> - if (urb->actual_length) {
> - tty_insert_flip_string(tty, data, urb->actual_length);
> - tty_flip_buffer_push(tty);
> - } else
> - dbg("%s: empty read urb received", __func__);
> + tty_insert_flip_string(tty, data, urb->actual_length);
> + tty_flip_buffer_push(tty);
> tty_kref_put(tty);
> + } else
And then you would want to change this to:
} else if (status == 0)
> + dbg("%s: empty read urb received", __func__);
>
> - /* Resubmit urb so we continue receiving */
> - if (status != -ESHUTDOWN) {
> - err = usb_submit_urb(urb, GFP_ATOMIC);
> - if (err && err != -EPERM)
> - printk(KERN_ERR "%s: resubmit read urb failed. "
> - "(%d)", __func__, err);
> - else
> - usb_mark_last_busy(port->serial->dev);
> - }
> +exit:
> + /* Resubmit urb so we continue receiving */
> + err = usb_submit_urb(urb, GFP_ATOMIC);
> + if (err && err != -EPERM)
> + printk(KERN_ERR "%s: resubmit read urb failed. "
> + "(%d)", __func__, err);
> + else
> + usb_mark_last_busy(port->serial->dev);
>
> - }
> return;
> }
As long as you're changing the code here, you might as well remove this
useless "return" statement.
Alan Stenr
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