tty_port: handle the nonblocking open of a dead port corner case

Some drivers allow O_NDELAY of a dead port (eg for setserial to work). In that
situation we must not try to raise the carrier.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Cox 2009-11-18 14:12:58 +00:00 committed by Greg Kroah-Hartman
parent a8a84540eb
commit 8627b96dd8

View File

@ -219,8 +219,11 @@ int tty_port_block_til_ready(struct tty_port *port,
/* if non-blocking mode is set we can pass directly to open unless
the port has just hung up or is in another error state */
if ((filp->f_flags & O_NONBLOCK) ||
(tty->flags & (1 << TTY_IO_ERROR))) {
if (tty->flags & (1 << TTY_IO_ERROR)) {
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
if (filp->f_flags & O_NONBLOCK) {
/* Indicate we are open */
if (tty->termios->c_cflag & CBAUD)
tty_port_raise_dtr_rts(port);