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USB: ir-usb: fix set_termios race

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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>
This commit is contained in:
Johan Hovold 2010-05-13 21:02:02 +02:00 committed by Greg Kroah-Hartman
parent 6f6ed69694
commit df66e8a2af
1 changed files with 57 additions and 26 deletions
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83
drivers/usb/serial/ir-usb.c
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@ -469,9 +469,23 @@ static void ir_read_bulk_callback(struct urb *urb)
return; 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, static void ir_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios) struct usb_serial_port *port, struct ktermios *old_termios)
{ {
struct urb *urb;
unsigned char *transfer_buffer; unsigned char *transfer_buffer;
int result; int result;
speed_t baud; speed_t baud;
@ -525,35 +539,52 @@ static void ir_set_termios(struct tty_struct *tty,
else else
ir_xbof = ir_xbof_change(xbof) ; 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 */ /* Only speed changes are supported */
tty_termios_copy_hw(tty->termios, old_termios); tty_termios_copy_hw(tty->termios, old_termios);
tty_encode_baud_rate(tty, baud, baud); 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) static int __init ir_init(void)