From fef062cbf2a90fd926a6fff9eb06dde1b699f1b3 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Sat, 10 Oct 2015 16:00:52 -0400 Subject: tty: Remove ASYNC_CLOSING checks in open()/hangup() methods Since at least before 2.6.30, tty drivers that do not drop the tty lock while closing cannot observe ASYNC_CLOSING set while holding the tty lock; this includes the tty driver's open() and hangup() methods, since the tty core calls these methods holding the tty lock. For these drivers, waiting for ASYNC_CLOSING to clear while opening is not required, since this condition cannot occur. Similarly, even when the open() method drops and reacquires the tty lock after blocking, ASYNC_CLOSING cannot be set (again, for drivers that do not drop the tty lock while closing). Now that tty port drivers no longer drop the tty lock while closing (since 'tty: Remove tty_wait_until_sent_from_close()'), the same conditions apply: waiting for ASYNC_CLOSING to clear while opening is not required, nor is re-checking ASYNC_CLOSING after dropping and reacquiring the tty lock while blocking (eg., in *_block_til_ready()). Note: The ASYNC_CLOSING flag state is still maintained since several bitrotting drivers use it for (dubious) other purposes. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- net/irda/ircomm/ircomm_tty.c | 31 +------------------------------ 1 file changed, 1 insertion(+), 30 deletions(-) (limited to 'net/irda') diff --git a/net/irda/ircomm/ircomm_tty.c b/net/irda/ircomm/ircomm_tty.c index 683346d2d633..a4237707f79d 100644 --- a/net/irda/ircomm/ircomm_tty.c +++ b/net/irda/ircomm/ircomm_tty.c @@ -335,8 +335,7 @@ static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self, * specified, we cannot return before the IrCOMM link is * ready */ - if (!test_bit(ASYNCB_CLOSING, &port->flags) && - (do_clocal || tty_port_carrier_raised(port)) && + if ((do_clocal || tty_port_carrier_raised(port)) && self->state == IRCOMM_TTY_READY) { break; @@ -443,34 +442,6 @@ static int ircomm_tty_open(struct tty_struct *tty, struct file *filp) /* Not really used by us, but lets do it anyway */ self->port.low_latency = (self->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0; - /* - * If the port is the middle of closing, bail out now - */ - if (test_bit(ASYNCB_CLOSING, &self->port.flags)) { - - /* Hm, why are we blocking on ASYNC_CLOSING if we - * do return -EAGAIN/-ERESTARTSYS below anyway? - * IMHO it's either not needed in the first place - * or for some reason we need to make sure the async - * closing has been finished - if so, wouldn't we - * probably better sleep uninterruptible? - */ - - if (wait_event_interruptible(self->port.close_wait, - !test_bit(ASYNCB_CLOSING, &self->port.flags))) { - net_warn_ratelimited("%s - got signal while blocking on ASYNC_CLOSING!\n", - __func__); - return -ERESTARTSYS; - } - -#ifdef SERIAL_DO_RESTART - return (self->port.flags & ASYNC_HUP_NOTIFY) ? - -EAGAIN : -ERESTARTSYS; -#else - return -EAGAIN; -#endif - } - /* Check if this is a "normal" ircomm device, or an irlpt device */ if (self->line < 0x10) { self->service_type = IRCOMM_3_WIRE | IRCOMM_9_WIRE; -- cgit v1.2.3-59-g8ed1b