Re: keyboard and USB problems (Re: 2.6.2-rc1-mm2)

From: john stultz
Date: Fri Jan 23 2004 - 14:29:41 EST


On Fri, 2004-01-23 at 08:19, Vojtech Pavlik wrote:
> On Fri, Jan 23, 2004 at 05:01:52PM +0100, Rudo Thomas wrote:
> > BogoMIPS is figured out to be 8.19 (this was already reported by another user),
>
> ... this the root cause of the following problems.
>
> > and i8042.c complaints with this:
> > i8042.c: Can't write CTR while closing AUX.
>
> ... bogomips is used in udelay() and that's used for waiting. If
> bogomips is measured lower than real, the wait takes shorter and the
> hardware doesn't do what it should in that short time.

Well, loops_per_jiffy is actually being measured correctly as we're
using the acpi pm timesource to time udelay(). However there is a loss
of resolution using the slower time source, so udelay(1) might take
longer then 1 us.

If that is going to cause problems, then we'll need to pull out the
use-pmtmr-for-delay_pmtmr patch. I guess our only option is then to use
the TSC for delay_pmtrm() (as a loop based delay fails in other cases).
I'll write that up and send it your way, Andrew.

thanks
-john


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/