Problems with hwclock
This page discusses the problem with /dev/rtc on certain models.
- 1 Problem description
- 2 Possible solutions
- 3 Affected Models
- 4 Affected Operating Systems
On bootup,a message like this shows up:
select() to /dev/rtc to wait for clock tick timed out
The RTC kernel driver can't handle the system clock.
Using the --directisa switch of hwclock(8)
The hwclock command knows the parameter --directisa to access the system clock "directly" instead of accessing it by using /dev/rtc. There are several ways of doing this automatically.
Move /sbin/hwclock (or wherever it is located on your system) to /sbin/hwclock.dist and create the following shell script, which you place at /sbin/hwclock
#!/bin/sh /sbin/hwclock.dist --directisa "$@"
Make the script executable (apply the same permissions you had for hwclock before) and keep your packaging system from overwriting it on updates.
Debian 4.0 (etch)
Add the following to /etc/default/rcS:
Debian 3.1 (sarge) and previous
Edit /etc/init.d/hwclock.sh and change all instances of "/sbin/hwclock" to "/sbin/hwclock --directisa".
Edit /etc/init.d/clock and set CLOCK_OPTS to
Compiling RTC-support into the kernel instead of as a module
Compiling RTC-support (CONFIG_RTC) into the kernel instead of compiling it as a module seems to work also. Tested on: 22.214.171.124 at Thinkpad Z61m 9450-3HG
- Thinkpad T60 (not all models)
- Thinkpad T61 (type 7662, maybe others)
- Thinkpad T60p
- Thinkpad X60s
- Thinkpad Z61m
Affected Operating Systems
- Linux, all flavours. Tested with kernel 2.6.18, 2.6.19, 126.96.36.199