hwclock: stream line synchronize_to_clock_tick_rtc()

Flip if clauses to hit common case first.  This should be easier and quicker
to read and run.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

1 files changed, 19 insertions, 22 deletions

diff --git a/sys-utils/hwclock-rtc.c b/sys-utils/hwclock-rtc.c
index f54e2633c..ba1882313 100644
--- a/sys-utils/hwclock-rtc.c
+++ b/sys-utils/hwclock-rtc.c
@@ -239,12 +239,12 @@ static int busywait_for_rtc_clock_tick(const struct hwclock_control *ctl,
 static int synchronize_to_clock_tick_rtc(const struct hwclock_control *ctl)
 {
 	int rtc_fd;		/* File descriptor of /dev/rtc */
-	int ret;
+	int ret = 1;
 
 	rtc_fd = open_rtc(ctl);
 	if (rtc_fd == -1) {
 		warn(_("cannot open rtc device"));
-		ret = 1;
+		return ret;
 	} else {
 		int rc;		/* Return code from ioctl */
 		/* Turn on update interrupts (one per second) */
@@ -258,18 +258,7 @@ static int synchronize_to_clock_tick_rtc(const struct hwclock_control *ctl)
 #else
 		rc = ioctl(rtc_fd, RTC_UIE_ON, 0);
 #endif
-		if (rc == -1 && (errno == ENOTTY || errno == EINVAL)) {
-			/*
-			 * This rtc device doesn't have interrupt functions.
-			 * This is typical on an Alpha, where the Hardware
-			 * Clock interrupts are used by the kernel for the
-			 * system clock, so aren't at the user's disposal.
-			 */
-			if (ctl->debug)
-				printf(_("%s does not have interrupt functions. "),
-				       rtc_dev_name);
-			ret = busywait_for_rtc_clock_tick(ctl, rtc_fd);
-		} else if (rc == 0) {
+		if (rc != -1) {
 			/*
 			 * Just reading rtc_fd fails on broken hardware: no
 			 * update interrupt comes and a bootscript with a
@@ -287,26 +276,34 @@ static int synchronize_to_clock_tick_rtc(const struct hwclock_control *ctl)
 			tv.tv_sec = 10;
 			tv.tv_usec = 0;
 			rc = select(rtc_fd + 1, &rfds, NULL, NULL, &tv);
-			ret = 1;
-			if (rc == -1)
-				warn(_("select() to %s to wait for clock tick failed"),
-				     rtc_dev_name);
+			if (0 < rc)
+				ret = 0;
 			else if (rc == 0) {
 				if (ctl->debug)
 					printf(_("select() to %s to wait for clock tick timed out"),
 					       rtc_dev_name);
 			} else
-				ret = 0;
+				warn(_("select() to %s to wait for clock tick failed"),
+				     rtc_dev_name);
 			/* Turn off update interrupts */
 			rc = ioctl(rtc_fd, RTC_UIE_OFF, 0);
 			if (rc == -1)
 				warn(_("ioctl() to %s to turn off update interrupts failed"),
 				     rtc_dev_name);
-		} else {
+		} else if (errno == ENOTTY || errno == EINVAL) {
+			/*
+			 * This rtc device doesn't have interrupt functions.
+			 * This is typical on an Alpha, where the Hardware
+			 * Clock interrupts are used by the kernel for the
+			 * system clock, so aren't at the user's disposal.
+			 */
+			if (ctl->debug)
+				printf(_("%s does not have interrupt functions. "),
+				       rtc_dev_name);
+			ret = busywait_for_rtc_clock_tick(ctl, rtc_fd);
+		} else
 			warn(_("ioctl() to %s to turn on update interrupts "
 			      "failed unexpectedly"), rtc_dev_name);
-			ret = 1;
-		}
 	}
 	return ret;
 }