[PATCH 3/3] Char: mxser, fix TIOCMIWAIT

From: Jiri Slaby
Date: Fri Apr 20 2007 - 06:36:30 EST


mxser, fix TIOCMIWAIT

There was schedule() missing in the TIOCMIWAIT ioctl. Solve it by moving
the code to the wait_event_interruptible.

Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>

---
commit 88c99e7bd7356c4b5a960f4a2b631d980bddc337
tree 4d713ce58282145839d6223a849c32a791e25a93
parent bd99756ce7fb8f3e9105b076a71046b0d8ad1f8f
author Jiri Slaby <jirislaby@xxxxxxxxx> Fri, 20 Apr 2007 12:26:08 +0200
committer Jiri Slaby <jirislaby@xxxxxxxxx> Fri, 20 Apr 2007 12:26:08 +0200

drivers/char/mxser.c | 48 ++++++++++++++----------------------------------
1 files changed, 14 insertions(+), 34 deletions(-)

diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 573b271..5953a45 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -1337,43 +1337,23 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file, unsigned int c
* (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);
+ cnow = info->icount; /* note the counters on entry */
+ spin_unlock_irqrestore(&info->slock, flags);
+
+ wait_event_interruptible(info->delta_msr_wait, ({
+ cprev = cnow;
spin_lock_irqsave(&info->slock, flags);
- cprev = info->icount; /* note the counters on entry */
+ cnow = info->icount; /* atomic copy */
spin_unlock_irqrestore(&info->slock, flags);

- add_wait_queue(&info->delta_msr_wait, &wait);
- while (1) {
- 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);
- break;
- }
- /* NOTREACHED */
+ ((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;
/*
* Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
* Return: write counters to the user passed counter struct
-
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