[LAD] Timers, hpet, hrtimer -> kind of solved (for too old motherboards)

Clemens Ladisch clemens at ladisch.de
Tue Nov 10 11:48:42 UTC 2009

hollunder at gmx.at wrote:
> $  dmesg | grep -i hpet
> Kernel command line: root=/dev/disk/by-uuid/3e47466f-5ca1-499b-85fc-152074f36364 ro hpet=force
> pci 0000:00:11.0: Failed to force enable HPET
> /dev/hpet was still created,

Then you have it.  The message is probably because it doesn't need
to be forced.

See /proc/iomem at address fed00000.

It's possible that your log buffer is too small and that the earlier
HPET messages were lost.  Do you have more HPET-releated messages
in /var/log/messages or /var/log/syslog?

> but when I changed its group and told jack to use it I got:
> This system has no accessible HPET device (Device or resource busy)

"Busy" means that it's there, but already being used.  Many motherboard
BIOSes do not initialize the third HPET interrupt, and the first two are
taken by the kernel.

Best regards,

More information about the Linux-audio-dev mailing list