System time runs with double speed on systems with ATI RS482 chipset

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Environment

SUSE Linux Enterprise Server 10
SUSE Linux Enterprise Desktop 10

Situation

The system clock runs with double speed on AMD64 and Intel EM64T (AMD64 systems with ATI RS482 chipset)

Resolution

The kernel parameter noapic needs to be set to the list of kernel boot parameters:

For systems using the grub bootloader, addnoapicto the kernel parameter of the default boot section.
For systems using lilo, add noapic to theappendparameter of the default image definition and runlilo.

To activate the change, reboot the system.

Additional Information

Some BIOS do not initialize the RS482 chipset correctly. In that case, the chipset delivers the timer tick both through the legacy interrupt controller as well as the APIC (Advanced Programmable Interrupt Controller), which results in two timer interrupts per tick. Specifying the kernel boot parameter noapic disables the APIC. The Linux kernel will then use the legacy interrupt controller instead.

Disclaimer

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