USB: ir-usb: fix set_termios race
Use dynamically allocated urb for baudrate changes rather than
unconditionally submitting the port write urb which may already be in
use.
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/ir-usb.c b/drivers/usb/serial/ir-usb.c
index aaebb70..d8490ea 100644
--- a/drivers/usb/serial/ir-usb.c
+++ b/drivers/usb/serial/ir-usb.c
@@ -469,9 +469,23 @@
return;
}
+static void ir_set_termios_callback(struct urb *urb)
+{
+ struct usb_serial_port *port = urb->context;
+ int status = urb->status;
+
+ dbg("%s - port %d", __func__, port->number);
+
+ kfree(urb->transfer_buffer);
+
+ if (status)
+ dbg("%s - non-zero urb status: %d", __func__, status);
+}
+
static void ir_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
+ struct urb *urb;
unsigned char *transfer_buffer;
int result;
speed_t baud;
@@ -525,35 +539,52 @@
else
ir_xbof = ir_xbof_change(xbof) ;
- /* FIXME need to check to see if our write urb is busy right
- * now, or use a urb pool.
- *
- * send the baud change out on an "empty" data packet
- */
- transfer_buffer = port->write_urb->transfer_buffer;
- *transfer_buffer = ir_xbof | ir_baud;
-
- usb_fill_bulk_urb(
- port->write_urb,
- port->serial->dev,
- usb_sndbulkpipe(port->serial->dev,
- port->bulk_out_endpointAddress),
- port->write_urb->transfer_buffer,
- 1,
- ir_write_bulk_callback,
- port);
-
- port->write_urb->transfer_flags = URB_ZERO_PACKET;
-
- result = usb_submit_urb(port->write_urb, GFP_KERNEL);
- if (result)
- dev_err(&port->dev,
- "%s - failed submitting write urb, error %d\n",
- __func__, result);
-
/* Only speed changes are supported */
tty_termios_copy_hw(tty->termios, old_termios);
tty_encode_baud_rate(tty, baud, baud);
+
+ /*
+ * send the baud change out on an "empty" data packet
+ */
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb) {
+ dev_err(&port->dev, "%s - no more urbs\n", __func__);
+ return;
+ }
+ transfer_buffer = kmalloc(1, GFP_KERNEL);
+ if (!transfer_buffer) {
+ dev_err(&port->dev, "%s - out of memory\n", __func__);
+ goto err_buf;
+ }
+
+ *transfer_buffer = ir_xbof | ir_baud;
+
+ usb_fill_bulk_urb(
+ urb,
+ port->serial->dev,
+ usb_sndbulkpipe(port->serial->dev,
+ port->bulk_out_endpointAddress),
+ transfer_buffer,
+ 1,
+ ir_set_termios_callback,
+ port);
+
+ urb->transfer_flags = URB_ZERO_PACKET;
+
+ result = usb_submit_urb(urb, GFP_KERNEL);
+ if (result) {
+ dev_err(&port->dev, "%s - failed to submit urb: %d\n",
+ __func__, result);
+ goto err_subm;
+ }
+
+ usb_free_urb(urb);
+
+ return;
+err_subm:
+ kfree(transfer_buffer);
+err_buf:
+ usb_free_urb(urb);
}
static int __init ir_init(void)