[PATCH] time: Fix get_ticks being non-monotonic

[Sean Anderson <seanga2@gmail.com>]

get_ticks does not always succeed. Sometimes it can be called before the
timer has been initialized. If it does, it returns a negative errno.
This causes the timer to appear non-monotonic, because the value will
become much smaller after the timer is initialized.

No users of get_ticks which I checked handle errors of this kind. Further,
functions like tick_to_time mangle the result of get_ticks, making it very
unlikely that one could check for an error without suggesting a patch such
as this one.

This patch changes get_ticks to always return 0 when there is an error.
0 is the least unsigned integer, ensuring get_ticks appears monotonic. This
has the side effect of time apparently not passing until the timer is
initialized. However, without this patch, time does not pass anyway,
because the error value is likely to be the same.

Fixes: c8a7ba9e6a5
Signed-off-by: Sean Anderson <seanga2@gmail.com>
---

 lib/time.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/time.c b/lib/time.c
index 47f8c84327..45750b6d36 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -91,13 +91,13 @@ uint64_t notrace get_ticks(void)
 
 		ret = dm_timer_init();
 		if (ret)
-			return ret;
+			return 0;
 #endif
 	}
 
 	ret = timer_get_count(gd->timer, &count);
 	if (ret)
-		return ret;
+		return 0;
 
 	return count;
 }
-- 
2.28.0