Radeon RV100 init fails with specific card+mobo - IRQ problem

[Meelis Roos]

> >> > Adding some printks reveals it calls
> >> > r100_init() -> radeon_irq_kms_init() -> drm_irq_install() ->
> >> > drm_dev_to_irq() and that fails. So no IRQ, no KMS.
> >> >
> >> > lspci does not show Interrupt like on some other PCI devices.
> >> > /proc/interrupts obviously does not contain the irq since we do not
> >> > register any yet.
> >> >
> >> > There is no BIOS option of "Enable IRQ for VGA" or similar (BIOS is
> >> > latest). Could this be the problem?
> >> >
> >> > What can I do to get KMS working on this computer?
> >> >
> >> > --
> >> > Meelis Roos (mroos at linux.ee)
> >>
> >> Try booting with radeon.agp_mode=-1
> >
> > radeon: `-1' invalid for parameter `agp_mode'
> 
> radeon.agpmode=-1
> 
> However, I think there are a number of places where we require
> interrupts that would need to be worked around (fences, display
> hotplug, pageflipping) if not interrupt is available.

I did dome more testing with different cards an got a surprise. The 
machine works fine with other AGP cards - one MX440 with nouvea, another 
RV100 QY and a R200. They do have interrupt in lspci -vvv output.

Why does this specific card not have its IRQ routed - card ROM problem?

-- 
Meelis Roos (mroos at linux.ee)