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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 63b4330..9756b5c22 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -259,21 +259,14 @@
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;
- }
- spin_unlock_irqrestore(&port->lock, flags);
-
- if (!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);
data = port->write_urb->transfer_buffer;
count = kfifo_out_locked(&port->write_fifo, data, port->bulk_out_size, &port->lock);