Re: slow clock on DELL Latitude 5501

[Frank Kardel <kardel%kardel.name@localhost>]

clockinterrupt be 4 times too slow explains the high TSC frequency(*4) 
and ACPI-Fast and hpet0 seem the have the same frequency scaling as 
clockinterrupt.

So it loock like the clockinterrupt setup is botched.

Best regards,

  Frank

On 02/11/20 17:10, is%netbsd.org@localhost wrote:
> Frank K. suggested:
>
> > TSC running at 10GHz on a 2.5GHz CPU looks a bit strange to me.
> > Try another timecounter, those frequencies look more like the ones
> > I am used to. Some is probaly wrong with the frquency estimation code
> > for TSC.
> I had thought of that, but didn't help. En detail:
>
> I have nearly always about 4 seconds between "sleep 1", but with
> some timecounters, displayed time (as of  "date") progresses not
> in 1 seconds, but in 4 second steps.
>
> 		sleep 1		date
> 		duration	increment
> --------------------------------------------
> TSC		~4 sec.		1 sec.
> clockinterupt	~4 sec.		1 sec.
> lapic		~4 sec.		1 sec.
> ACPI-Fast	~4 sec.		4-5 sec.
> hpet0		~4 sec.		4-5 sec.
> i8254		very long	?
> dummy		very long	?
> --------------------------------------------
>
> for the 8.1 kernel, the difference seems to be that on i8254 and
> dummy sleep 1 takes 4 seconds, but the time doesn't progress:
>
> --------------------------------------------
> TSC		~4 sec.		1 sec.
> clockinterupt	~4 sec.		1 sec.
> lapic		~4 sec.		1 sec.
> hpet0		~4 sec.		4-5 sec.
> ACPI-Fast	~4 sec.		4-5 sec.
> i8254		~4 sec.		<0.03 sec.
> dummy		~4 sec.		<0.03 sec.
> --------------------------------------------
>
> is writing
>
> sysctl -w kern.timecounter.hardware=...
>
> the right method to switch, or do I need to disable
> the TSC one by userconf when booting to make the clock
> interupt use different hardware?
>
> 	-is