git » linux-kernel » commit 8627b96

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

author Alan Cox
2009-11-18 14:12:58 UTC
committer Greg Kroah-Hartman
2009-12-01 00:38:25 UTC
parent a8a84540eb3fd0493f250dc1c513bef6810a50fd
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>
drivers/char/tty_port.c +5 -2 
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 2e8552dc5ed..c63f3d33914 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -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);