Commit 50a5f70c authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman

USB: serial: clean up generic write start busy test

Submit write urb if it is not already in use and we have buffered data.
Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 1a1405e2
......@@ -259,22 +259,15 @@ static int usb_serial_generic_write_start(struct usb_serial_port *port)
int result;
int count;
unsigned long flags;
bool start_io;
/* Atomically determine whether we can and need to start a USB
* operation. */
spin_lock_irqsave(&port->lock, flags);
if (port->write_urb_busy)
start_io = false;
else {
start_io = (kfifo_len(&port->write_fifo) != 0);
port->write_urb_busy = start_io;
if (port->write_urb_busy || !kfifo_len(&port->write_fifo)) {
spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
port->write_urb_busy = 1;
spin_unlock_irqrestore(&port->lock, flags);
if (!start_io)
return 0;
data = port->write_urb->transfer_buffer;
count = kfifo_out_locked(&port->write_fifo, data, port->bulk_out_size, &port->lock);
usb_serial_debug_data(debug, &port->dev, __func__, count, data);
......
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