USB: omninet: clean up write-urb busy handling

Use port write_urbs_free mask rather than write_urb_busy field in struct
serial_port.

Compile-only tested.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c
index 6e97664..1594bde 100644 (file)
--- a/drivers/usb/serial/omninet.c
+++ b/drivers/usb/serial/omninet.c
@@ -19,7 +19,6 @@
 #include <linux/tty_driver.h>
 #include <linux/tty_flip.h>
 #include <linux/module.h>
-#include <linux/spinlock.h>
 #include <linux/uaccess.h>
 #include <linux/usb.h>
 #include <linux/usb/serial.h>
@@ -242,14 +241,10 @@ static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
                return 0;
        }
 
-       spin_lock_bh(&wport->lock);
-       if (wport->write_urb_busy) {
-               spin_unlock_bh(&wport->lock);
+       if (!test_and_clear_bit(0, &port->write_urbs_free)) {
                dbg("%s - already writing", __func__);
                return 0;
        }
-       wport->write_urb_busy = 1;
-       spin_unlock_bh(&wport->lock);
 
        count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
 
@@ -270,7 +265,7 @@ static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
        wport->write_urb->dev = serial->dev;
        result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
        if (result) {
-               wport->write_urb_busy = 0;
+               set_bit(0, &wport->write_urbs_free);
                dev_err(&port->dev,
                        "%s - failed submitting write urb, error %d\n",
                        __func__, result);
@@ -289,8 +284,7 @@ static int omninet_write_room(struct tty_struct *tty)
 
        int room = 0; /* Default: no room */
 
-       /* FIXME: no consistent locking for write_urb_busy */
-       if (!wport->write_urb_busy)
+       if (test_bit(0, &wport->write_urbs_free))
                room = wport->bulk_out_size - OMNINET_HEADERLEN;
 
        dbg("%s - returns %d", __func__, room);
@@ -307,7 +301,7 @@ static void omninet_write_bulk_callback(struct urb *urb)
 
        dbg("%s - port %0x", __func__, port->number);
 
-       port->write_urb_busy = 0;
+       set_bit(0, &port->write_urbs_free);
        if (status) {
                dbg("%s - nonzero write bulk status received: %d",
                    __func__, status);