Arch Linux

My new laptop requires the --directisa option for hwclock calls otherwise it will fail

$ LANG=en_US hwclock --debug
hwclock from util-linux-2.12r
Using /dev/rtc interface to clock.
Last drift adjustment done at 1147832697 seconds after 1969
Last calibration done at 1147832697 seconds after 1969
Hardware clock is on local time
Assuming hardware clock is kept in local time.
Waiting for clock tick...
select() to /dev/rtc to wait for clock tick timed out
...got clock tick

and the clock will be set incorrectly (two hours ahead)


--directisa should be harmless according to the man page:

--directisa
is meaningful only on an ISA machine or an Alpha (which imple-
ments enough of ISA to be, roughly speaking, an ISA machine for
hwclock's purposes). For other machines, it has no effect.
This option tells hwclock to use explicit I/O instructions to
access the Hardware Clock. Without this option, hwclock will
try to use the /dev/rtc device (which it assumes to be driven
by the rtc device driver). If it is unable to open the device
(for read), it will use the explicit I/O instructions anyway.

The rtc device driver was new in Linux Release 2.