diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2015-10-10 16:00:52 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-17 21:11:29 -0700 |
| commit | fef062cbf2a90fd926a6fff9eb06dde1b699f1b3 (patch) | |
| tree | 5f2cc71db26e745beb483d96b0005b6d9cdd2714 /drivers/tty/serial/crisv10.c | |
| parent | 79c1faa4511e78380cd643dac88a775062a08bc0 (diff) | |
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 <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/crisv10.c')
| -rw-r--r-- | drivers/tty/serial/crisv10.c | 33 |
1 files changed, 1 insertions, 32 deletions
diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c index 3e4470af5c50..06f4fe928dcd 100644 --- a/drivers/tty/serial/crisv10.c +++ b/drivers/tty/serial/crisv10.c @@ -3759,23 +3759,6 @@ block_til_ready(struct tty_struct *tty, struct file * filp, int do_clocal = 0; /* - * If the device is in the middle of being closed, then block - * until it's done, and then try again. - */ - if (info->port.flags & ASYNC_CLOSING) { - wait_event_interruptible_tty(tty, info->port.close_wait, - !(info->port.flags & ASYNC_CLOSING)); -#ifdef SERIAL_DO_RESTART - if (info->port.flags & ASYNC_HUP_NOTIFY) - return -EAGAIN; - else - return -ERESTARTSYS; -#else - return -EAGAIN; -#endif - } - - /* * If non-blocking mode is set, or the port is not enabled, * then make the check up front and then exit. */ @@ -3825,7 +3808,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp, #endif break; } - if (!(info->port.flags & ASYNC_CLOSING) && do_clocal) + if (do_clocal) /* && (do_clocal || DCD_IS_ASSERTED) */ break; if (signal_pending(current)) { @@ -3895,20 +3878,6 @@ rs_open(struct tty_struct *tty, struct file * filp) info->port.low_latency = !!(info->port.flags & ASYNC_LOW_LATENCY); /* - * If the port is in the middle of closing, bail out now - */ - if (info->port.flags & ASYNC_CLOSING) { - wait_event_interruptible_tty(tty, info->port.close_wait, - !(info->port.flags & ASYNC_CLOSING)); -#ifdef SERIAL_DO_RESTART - return ((info->port.flags & ASYNC_HUP_NOTIFY) ? - -EAGAIN : -ERESTARTSYS); -#else - return -EAGAIN; -#endif - } - - /* * If DMA is enabled try to allocate the irq's. */ if (info->port.count == 1) { |