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tty: introduce wait_event_interruptible_tty

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Calling wait_event_interruptible implicitly
releases the BKL when it sleeps, but we need
to do this explcitly when we have converted
it to a mutex.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Arnd Bergmann 2010-06-01 22:53:05 +02:00 committed by Greg Kroah-Hartman
parent 4e60867167
commit be1bc2889a
7 changed files with 59 additions and 10 deletions
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2
drivers/char/cyclades.c
View File

@ -1607,7 +1607,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
* If the port is the middle of closing, bail out now
*/
if (tty_hung_up_p(filp) || (info->port.flags & ASYNC_CLOSING)) {
wait_event_interruptible(info->port.close_wait,
wait_event_interruptible_tty(info->port.close_wait,
!(info->port.flags & ASYNC_CLOSING));
return (info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN: -ERESTARTSYS;
}

12
drivers/char/istallion.c
View File

@ -954,7 +954,7 @@ static int stli_rawopen(struct stlibrd *brdp, struct stliport *portp, unsigned l
* order of opens and closes may not be preserved across shared
* memory, so we must wait until it is complete.
*/
wait_event_interruptible(portp->raw_wait,
wait_event_interruptible_tty(portp->raw_wait,
!test_bit(ST_CLOSING, &portp->state));
if (signal_pending(current)) {
return -ERESTARTSYS;
@ -989,7 +989,7 @@ static int stli_rawopen(struct stlibrd *brdp, struct stliport *portp, unsigned l
set_bit(ST_OPENING, &portp->state);
spin_unlock_irqrestore(&brd_lock, flags);
wait_event_interruptible(portp->raw_wait,
wait_event_interruptible_tty(portp->raw_wait,
!test_bit(ST_OPENING, &portp->state));
if (signal_pending(current))
rc = -ERESTARTSYS;
@ -1020,7 +1020,7 @@ static int stli_rawclose(struct stlibrd *brdp, struct stliport *portp, unsigned
* occurs on this port.
*/
if (wait) {
wait_event_interruptible(portp->raw_wait,
wait_event_interruptible_tty(portp->raw_wait,
!test_bit(ST_CLOSING, &portp->state));
if (signal_pending(current)) {
return -ERESTARTSYS;
@ -1052,7 +1052,7 @@ static int stli_rawclose(struct stlibrd *brdp, struct stliport *portp, unsigned
* to come back.
*/
rc = 0;
wait_event_interruptible(portp->raw_wait,
wait_event_interruptible_tty(portp->raw_wait,
!test_bit(ST_CLOSING, &portp->state));
if (signal_pending(current))
rc = -ERESTARTSYS;
@ -1073,6 +1073,10 @@ static int stli_rawclose(struct stlibrd *brdp, struct stliport *portp, unsigned
static int stli_cmdwait(struct stlibrd *brdp, struct stliport *portp, unsigned long cmd, void *arg, int size, int copyback)
{
/*
* no need for wait_event_tty because clearing ST_CMDING cannot block
* on BTM
*/
wait_event_interruptible(portp->raw_wait,
!test_bit(ST_CMDING, &portp->state));
if (signal_pending(current))

2
drivers/char/n_r3964.c
View File

@ -1079,7 +1079,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
goto unlock;
}
/* block until there is a message: */
wait_event_interruptible(pInfo->read_wait,
wait_event_interruptible_tty(pInfo->read_wait,
(pMsg = remove_msg(pInfo, pClient)));
}

2
drivers/char/tty_port.c
View File

@ -231,7 +231,7 @@ int tty_port_block_til_ready(struct tty_port *port,
/* block if port is in the process of being closed */
if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
wait_event_interruptible(port->close_wait,
wait_event_interruptible_tty(port->close_wait,
!(port->flags & ASYNC_CLOSING));
if (port->flags & ASYNC_HUP_NOTIFY)
return -EAGAIN;

5
drivers/char/vt_ioctl.c
View File

@ -133,7 +133,7 @@ static void vt_event_wait(struct vt_event_wait *vw)
list_add(&vw->list, &vt_events);
spin_unlock_irqrestore(&vt_event_lock, flags);
/* Wait for it to pass */
wait_event_interruptible(vt_event_waitqueue, vw->done);
wait_event_interruptible_tty(vt_event_waitqueue, vw->done);
/* Dequeue it */
spin_lock_irqsave(&vt_event_lock, flags);
list_del(&vw->list);
@ -1761,10 +1761,13 @@ int vt_move_to_console(unsigned int vt, int alloc)
return -EIO;
}
release_console_sem();
tty_lock();
if (vt_waitactive(vt + 1)) {
pr_debug("Suspend: Can't switch VCs.");
tty_unlock();
return -EINTR;
}
tty_unlock();
return prev;
}

4
drivers/serial/crisv10.c
View File

@ -3992,7 +3992,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp,
*/
if (tty_hung_up_p(filp) ||
(info->flags & ASYNC_CLOSING)) {
wait_event_interruptible(info->close_wait,
wait_event_interruptible_tty(info->close_wait,
!(info->flags & ASYNC_CLOSING));
#ifdef SERIAL_DO_RESTART
if (info->flags & ASYNC_HUP_NOTIFY)
@ -4150,7 +4150,7 @@ rs_open(struct tty_struct *tty, struct file * filp)
*/
if (tty_hung_up_p(filp) ||
(info->flags & ASYNC_CLOSING)) {
wait_event_interruptible(info->close_wait,
wait_event_interruptible_tty(info->close_wait,
!(info->flags & ASYNC_CLOSING));
#ifdef SERIAL_DO_RESTART
return ((info->flags & ASYNC_HUP_NOTIFY) ?

42
include/linux/tty.h
View File

@ -607,5 +607,47 @@ static inline void tty_unlock(void) __releases(kernel_lock)
}
#define tty_locked() (kernel_locked())
/*
* wait_event_interruptible_tty -- wait for a condition with the tty lock held
*
* The condition we are waiting for might take a long time to
* become true, or might depend on another thread taking the
* BTM. In either case, we need to drop the BTM to guarantee
* forward progress. This is a leftover from the conversion
* from the BKL and should eventually get removed as the BTM
* falls out of use.
*
* Do not use in new code.
*/
#define wait_event_interruptible_tty(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) { \
__wait_event_interruptible_tty(wq, condition, __ret); \
} \
__ret; \
})
#define __wait_event_interruptible_tty(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (!signal_pending(current)) { \
tty_unlock(); \
schedule(); \
tty_lock(); \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)
#endif /* __KERNEL__ */
#endif