swi4: clock sio uses 10% cpu

[Helge Oldach]

Holger,

>puc0: <Titan PCI-800H> port 0xa400-0xa41f,0xa000-0xa01f mem 0xdf800000-0xdf800fff,0xdf000000-0xdf000fff irq 10 at device 11.0 on pci0
>puc1: <Titan PCI-800H> port 0x9800-0x981f,0x9400-0x941f mem 0xde800000-0xde800fff,0xde000000-0xde000fff irq 10 at device 11.1 on pci0

The Titan device shows up as two PCI devices with shared interrupt.
Shared interrupts are supported by the puc(4) driver, but not in fast
interrupt mode. This eats a lot of CPU, causes silo overflows and
character loss. This is what the kernel tells you:

>sio12: unable to activate interrupt in fast mode - using normal mode

If possible try to make these two different irqs, or disable "half of
the board".

Helge