Clock offsets during suspend/resume
andy at openmoko.com
Fri Dec 12 16:48:22 CET 2008
-----BEGIN PGP SIGNED MESSAGE-----
Somebody in the thread at some point said:
|> I would guess the effect could be mainly caused by sitting there
|> scrolling the Glamo framebuffer, if you try it without console=tty0 on
|> cmdline does it impact it?
| Using 'echo 0 0 0 0 > /proc/sys/kernel/printk' it suspends and resumes a
| lot faster and doesn't pick up any delay. Even after several cycles, the
| sum is still below 1 second.
Hm well the default state with Qi going on is going to be no noncritical
syslog on the LCM.
| The weird thing is that even now, it still has an offset of 51 seconds
| between system and hw clock. So it does not seem to restore from the hw
| clock accessible via 'hwclock'... or does it remember the offset during
Seems that the rtc class stuff does indeed take care of that
/* restore wall clock using delta against this RTC;
* adjust again for avg 1/2 second RTC sampling error
newtime + delta.tv_sec,
(NSEC_PER_SEC >> 1) + delta.tv_nsec);
... I guess it is for maintaining timezone offset from a UTC hw rtc.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org
-----END PGP SIGNATURE-----
More information about the openmoko-kernel