diff options
Diffstat (limited to 'drivers/char/mxser_new.c')
| -rw-r--r-- | drivers/char/mxser_new.c | 45 |
1 files changed, 16 insertions, 29 deletions
diff --git a/drivers/char/mxser_new.c b/drivers/char/mxser_new.c index 9af07e4999d5..f7603b6aeb87 100644 --- a/drivers/char/mxser_new.c +++ b/drivers/char/mxser_new.c @@ -1758,43 +1758,23 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file, * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) * Caller should use TIOCGICOUNT to see which one it was */ - case TIOCMIWAIT: { - DECLARE_WAITQUEUE(wait, current); - int ret; + case TIOCMIWAIT: spin_lock_irqsave(&info->slock, flags); - cprev = info->icount; /* note the counters on entry */ + cnow = info->icount; /* note the counters on entry */ spin_unlock_irqrestore(&info->slock, flags); - add_wait_queue(&info->delta_msr_wait, &wait); - while (1) { + wait_event_interruptible(info->delta_msr_wait, ({ + cprev = cnow; spin_lock_irqsave(&info->slock, flags); cnow = info->icount; /* atomic copy */ spin_unlock_irqrestore(&info->slock, flags); - set_current_state(TASK_INTERRUPTIBLE); - if (((arg & TIOCM_RNG) && - (cnow.rng != cprev.rng)) || - ((arg & TIOCM_DSR) && - (cnow.dsr != cprev.dsr)) || - ((arg & TIOCM_CD) && - (cnow.dcd != cprev.dcd)) || - ((arg & TIOCM_CTS) && - (cnow.cts != cprev.cts))) { - ret = 0; - break; - } - /* see if a signal did it */ - if (signal_pending(current)) { - ret = -ERESTARTSYS; - break; - } - cprev = cnow; - } - current->state = TASK_RUNNING; - remove_wait_queue(&info->delta_msr_wait, &wait); + ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || + ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || + ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || + ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)); + })); break; - } - /* NOTREACHED */ /* * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) * Return: write counters to the user passed counter struct @@ -2230,7 +2210,14 @@ end_intr: port->mon_data.rxcnt += cnt; port->mon_data.up_rxcnt += cnt; + /* + * We are called from an interrupt context with &port->slock + * being held. Drop it temporarily in order to prevent + * recursive locking. + */ + spin_unlock(&port->slock); tty_flip_buffer_push(tty); + spin_lock(&port->slock); } static void mxser_transmit_chars(struct mxser_port *port) |