/* write data to ring buffer. and then start the write transfer */
static int spcp8x5_write(struct usb_serial_port *port,
const unsigned char *buf, int count)
{
struct spcp8x5_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
dev_dbg(&port->dev, "%d bytes\n", count);
if (!count)
return count;
spin_lock_irqsave(&priv->lock, flags);
count = put_ringbuf(priv->buf, buf, count);
spin_unlock_irqrestore(&priv->lock, flags);
spcp8x5_send(port);
return count;
}
/* this is the call back function for write urb. NOTE we should not sleep in
* this routine. check the urb return code and then submit the write urb again
* to hold the write loop */
static void spcp8x5_write_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct spcp8x5_private *priv = usb_get_serial_port_data(port);
int result;
int status = urb->status;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dev_dbg(&port->dev, "urb shutting down with status: %d\n",
status);
priv->write_urb_in_use = 0;
return;
default:
/* error in the urb, so we have to resubmit it */
dbg("%s - Overflow in write", __func__);
dbg("%s - nonzero write bulk status received: %d",
__func__, status);
port->write_urb->transfer_buffer_length = 1;
port->write_urb->dev = port->serial->dev;
result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (result)
dev_dbg(&port->dev,
"failed resubmitting write urb %d\n", result);
else
return;
}
priv->write_urb_in_use = 0;
/* send any buffered data */
spcp8x5_send(port);
}
