Use the us_to_timeval helper function in the avalon driver.
diff --git a/driver-avalon.c b/driver-avalon.c
index 8fca350..728e316 100644
--- a/driver-avalon.c
+++ b/driver-avalon.c
@@ -1300,8 +1300,7 @@ static int64_t avalon_scanhash(struct thr_info *thr)
/* Half nonce range */
us_timeout = 0x80000000ll / info->asic_count / info->frequency;
- tdiff.tv_sec = us_timeout / 1000000;
- tdiff.tv_usec = us_timeout - (tdiff.tv_sec * 1000000);
+ us_to_timeval(&tdiff, us_timeout);
cgtime(&now);
timeradd(&now, &tdiff, &then);
timeval_to_spec(&abstime, &then);