Time running

Balaji Rao balaji at raobalaji.com
Mon Oct 6 12:15:12 CEST 2008


On Mon, 6 Oct 2008 00:51:57 +0200
"andrzej zaborowski" <balrogg at gmail.com> wrote:

> Hi,
> 
> 2008/10/6 Balaji Rao <balaji at raobalaji.com>:
> > On Wed, 01 Oct 2008 15:05:22 +0100
> > Andy Green <andy at openmoko.com> wrote:
> >> | How do I fix this ? I've noticed that the number of timer
> >> interrupts | received is ~6x lesser. I wonder what the problem
> >> really is. Are the | interrupts not delivered at the required rate
> >> and is there a way I can | test this ?
> >> |
> >> | Suggestions welcome.
> >>
> >> I'm working on adding the andy-2.6.26 stuff to andy-tracking right
> >> now and seeing the same.
> >>
> >> Previously (some weeks ago) on tracking there was trouble with hdq
> >> that I put down to PWM init affecting the timer used for FIQ
> >> generation.  I moved the FIQ timer to another PWM unit and the
> >> problems went away. Since then FIQ is trashed by later changes
> >> upstream I am trying to figure out now.
> >>
> >> Anyway I would dump the PWM-related registers from CPU on 2.6.24 or
> >> 2.6.26 and current tracking and compare them, it seems it might
> >> give a clue.
> >
> > Andy,
> >
> > I've narrowed down the problem to the following change upstream.
> 
> If you're still fighting the timer going too slow issue, apparently
> it's seen on all S3C24xx machines except the Simtec ones (that use
> tclk input) and it's been discussen on LAKML and there was a fix
> posted:
> 
> http://marc.info/?t=122293014600003&r=1&w=2
> 
> I used this when developing the GENERIC_TIME / GENERIC_CLOCKEVENTS
> support recently and it worked for me.

Cool. Has it gone upstream ?

Anyways I learnt a lot about a3c24xx timers chasing this one! :)

	- Balaji



More information about the openmoko-kernel mailing list