Char: mxser_new, fix TIOCMIWAIT

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

Cc: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 29 deletions

diff --git a/drivers/char/mxser_new.c b/drivers/char/mxser_new.c
index 59e0aac19c2f..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