The masks were 0, so 0x3e2 was ORed into the reset value 0xbff and both
SerDes stayed off on boards without 10G ports (n_10g == 0), e.g. the
HC-SWTG124AS. With SDS 0 off RTL837X_REG_SEC_COUNTER does not hold a
written value: it reads 0, so NTP never retried after a failed first
attempt at boot and froze the clock after a sync.
Tested with regset on an HC-SWTG124AS: the register keeps a write with
SDS 0 in SGMII or 10GR, not with SDS 0 off (also not with only SDS 1
on).
Firefox filled a saved login into the System tab's password fields and
its user name into the NTP poll interval, the input before them. That
input event marked the Time card as edited, so ntpLoad() left NTP off,
the server empty and the time zone at UTC-12:00.