Section 9.21. Timer-Specific Options

9.21. Timer-Specific Options

These options override default kernel behavior to fix problems with certain chips.

Enable pin 1 of the APIC timer.

Enable pin 1 of the APIC timer. This option can be useful to work around chipset bugs (on some ATI chipsets in particular). The kernel tries to set a reasonable default, but sometimes this option is necessary to override it.

Disable pin 1 of the APIC timer.

Disable pin 1 of the APIC timer. Useful for the same reasons as enable_timer_pin_1.

Enable interrupt 0 timer routing over the 8254 chip.

Enable interrupt 0 timer routing over the 8254 chip in addition to routing over the IO-APIC. The kernel tries to set a reasonable default, but sometimes this option is necessary to override it.

Disable interrupt 0 timer routing over the 8254 chip.

Disable interrupt 0 timer routing over the 8254 chip in addition to routing over the IO-APIC. The kernel tries to set a reasonable default, but sometimes this option is necessary to override it.

Disable HPET and use PIT instead.

hpet=disable

Disable the HPET timer source and tell the kernel to use the PIT timer source instead.

Set the specific clocksource.

clocksource=[hpet|pit|tsc|acpi_pm|cyclone|scx200_hrt]

Override the default kernel clocksource and use the clocksource with the specified name instead.