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>
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 2e8552d..c63f3d3 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -219,8 +219,11 @@
/* 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);