Original discussion: http://thread.gmane.org/gmane.linux.usb.general/23217/focus=23248 or http://marc.info/?l=linux-usb&m=125553790714133&w=2 From: Alan Cox <alan@xxxxxxxxxxxxxxx> The tty_port code inherited a bug common to various drivers it was based upon. If the tty is opened O_NONBLOCK we do not wait for the carrier to be raised but we must still raise our modem lines if appropriate. (There is a second question here about whether we should do so if CLOCAL is set but that can wait) Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx> Reported-by: Karl Hiramoto <karl@xxxxxxxxxxxx> Tested-by: Karl Hiramoto <karl@xxxxxxxxxxxx> --- drivers/char/tty_port.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index a4bbb28..2e8552d 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -221,6 +221,9 @@ int tty_port_block_til_ready(struct tty_port *port, the port has just hung up or is in another error state */ if ((filp->f_flags & O_NONBLOCK) || (tty->flags & (1 << TTY_IO_ERROR))) { + /* Indicate we are open */ + if (tty->termios->c_cflag & CBAUD) + tty_port_raise_dtr_rts(port); port->flags |= ASYNC_NORMAL_ACTIVE; return 0; } -- 1.6.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
