Commit 3c5b2f5b authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
Browse files

tty: Drop duplicate NULL check in TTY port functions 



The free_page(addr), which becomes free_pages(addr, 0) checks addr against 0.
No need to repeat this check in the callers, i.e.  tty_port_free_xmit_buf()
and tty_port_destructor().

Note, INIT_KFIFO() is safe without that check, because it operates on
a separate member and doesn't rely on the FIFO itself to be allocated.

Acked-by: default avatarJiri Slaby <jirislaby@kernel.org>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220204153253.11006-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 916acbf6

drivers/tty/tty_port.c

+4 −7
Original line number Diff line number Diff line
@@ -240,11 +240,9 @@ EXPORT_SYMBOL(tty_port_alloc_xmit_buf); 
void tty_port_free_xmit_buf(struct tty_port *port)

{

	mutex_lock(&port->buf_mutex);

	if (port->xmit_buf != NULL) {

	free_page((unsigned long)port->xmit_buf);

	port->xmit_buf = NULL;

	INIT_KFIFO(port->xmit_fifo);

	}

	mutex_unlock(&port->buf_mutex);

}

EXPORT_SYMBOL(tty_port_free_xmit_buf);
@@ -271,7 +269,6 @@ static void tty_port_destructor(struct kref *kref) 
	/* check if last port ref was dropped before tty release */

	if (WARN_ON(port->itty))

		return;

	if (port->xmit_buf)

	free_page((unsigned long)port->xmit_buf);

	tty_port_destroy(port);

	if (port->ops && port->ops->destruct)