Rune Torgersen writes:
> The main couse is that our main bus frequency cannort be divided into
> 1kHz evently by the decrementer.
> Main bus freq = 99532800 Hz.
> Decrementer then becomes 24883, which gives us 91.9624485600nsec per
> jiffy.
> That is not a number easilly converted into time wi
On Mon, 2007-10-15 at 16:50 -0500, Rune Torgersen wrote:
> Huh? Not in 2.6.18/arch/ppc at least, unless I'm completely
> misundrstanding the code.
> ppc/powerpc seems to be using clocksource_jiffies as the clock source,
> and teh gettimeofday gets xtime + a offset from last jiffie, and xtime
> is
> From: Benjamin Herrenschmidt>
> > The TB register is only ued for offsets from the last
> jiffie, not as a
> > continous offset, so then it works out pretty good.
>
> The date is derived from the absolute TB value though...
Huh? Not in 2.6.18/arch/ppc at least, unless I'm completely
misundrsta
On Mon, 2007-10-15 at 11:49 -0500, Rune Torgersen wrote:
>
> The main couse is that our main bus frequency cannort be divided into
> 1kHz evently by the decrementer.
> Main bus freq = 99532800 Hz.
> Decrementer then becomes 24883, which gives us 91.9624485600nsec
> per
> jiffy.
> That is not
> From: Benjamin Herrenschmidt
> In fact, I'm not sure what is your problem with the DEC
> proper as the TB
> will be used ultimately and thus it shouldn't drift more than the TB
> does. Can your part use an externally clocked TB ?
>
> If not, and you still have a drift despite calibration, you c
On Fri, 2007-10-12 at 16:39 -0500, Rune Torgersen wrote:
> > From: Mark A. Greer
> > > Is there an easy way to use something other than the decrementer for
> the
> > > timer interrupt?
>
> > Check out the clocksource stuff. It let's you set up numerous clock
> > sources and set the rating of ea
On Fri, Oct 12, 2007 at 04:39:53PM -0500, Rune Torgersen wrote:
> > From: Mark A. Greer
> > > Is there an easy way to use something other than the decrementer for
> the
> > > timer interrupt?
>
> > Check out the clocksource stuff. It let's you set up numerous clock
> > sources and set the rating
> From: Mark A. Greer
> > Is there an easy way to use something other than the decrementer for
the
> > timer interrupt?
> Check out the clocksource stuff. It let's you set up numerous clock
> sources and set the rating of each one. You can start looking in
> arch/powerpc/kernel/time.c for examp
On Fri, Oct 12, 2007 at 03:49:02PM -0500, Rune Torgersen wrote:
> Is there an easy way to use something other than the decrementer for the
> timer interrupt?
>
> Reason i'm asking is tha t on our board, the decrementer cannot be
> divided to 1khz evenly, so we have rounding errors for time, but we
