Change in coreboot[master]: lib/timer: Make udelay respect input parameter

[Raul Rangel (Code Review)]

Raul Rangel has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/56268 )

Change subject: lib/timer: Make udelay respect input parameter
......................................................................

lib/timer: Make udelay respect input parameter

This makes it possible to use `udelay(0)` to yield without actually
wasting 1 us.

BUG=b:179699789
TEST=Boot guybrush to the OS

Signed-off-by: Raul E Rangel 
Change-Id: I03c842ecef7641009f177a1458b88ca500dbfdb4
---
M src/lib/timer.c
1 file changed, 4 insertions(+), 8 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/68/56268/1

diff --git a/src/lib/timer.c b/src/lib/timer.c
index 8a06f57..411e60e 100644
--- a/src/lib/timer.c
+++ b/src/lib/timer.c
@@ -10,15 +10,11 @@
 {
    struct stopwatch sw;

-	/*
-	 * As the timer granularity is in microseconds pad the
-	 * requested delay by one to get at least >= requested usec delay.
-	 */
-	usec += 1;
-
    if (!thread_yield_microseconds(usec))
    	return;

-	stopwatch_init_usecs_expire(&sw, usec);
-	stopwatch_wait_until_expired(&sw);
+	if (usec > 0) {
+		stopwatch_init_usecs_expire(&sw, usec);
+		stopwatch_wait_until_expired(&sw);
+	}
 }