X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Ftty%2Famiserial.c;h=979e7c3ea2cbc25e3cffbc0b50280414f97c09cf;hb=0214196ce0e941256797bf54b2fcf1450452df2a;hp=71630a2af42ccf5f2eb48ea79793cadca86ab5c6;hpb=825e587af2e90e9b953849f3347a01d8f383d577;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 71630a2af42c..979e7c3ea2cb 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1248,6 +1248,8 @@ static int rs_ioctl(struct tty_struct *tty,
 	struct async_icount cprev, cnow;	/* kernel counter temps */
 	void __user *argp = (void __user *)arg;
 	unsigned long flags;
+	DEFINE_WAIT(wait);
+	int ret;
 
 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
 		return -ENODEV;
@@ -1288,25 +1290,33 @@ static int rs_ioctl(struct tty_struct *tty,
 			cprev = info->icount;
 			local_irq_restore(flags);
 			while (1) {
-				interruptible_sleep_on(&info->tport.delta_msr_wait);
-				/* see if a signal did it */
-				if (signal_pending(current))
-					return -ERESTARTSYS;
+				prepare_to_wait(&info->tport.delta_msr_wait,
+						&wait, TASK_INTERRUPTIBLE);
 				local_irq_save(flags);
 				cnow = info->icount; /* atomic copy */
 				local_irq_restore(flags);
 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
-				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
-					return -EIO; /* no change => error */
+				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
+					ret = -EIO; /* no change => error */
+					break;
+				}
 				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)) ) {
-					return 0;
+					ret = 0;
+					break;
+				}
+				schedule();
+				/* see if a signal did it */
+				if (signal_pending(current)) {
+					ret = -ERESTARTSYS;
+					break;
 				}
 				cprev = cnow;
 			}
-			/* NOTREACHED */
+			finish_wait(&info->tport.delta_msr_wait, &wait);
+			return ret;
 
 		case TIOCSERGWILD:
 		case TIOCSERSWILD: