[Intel-gfx] Patch for testing irq spinning

[Pierre Willenbrock]

Keith Packard schrieb:
> On Thu, 2008-12-04 at 15:43 +0100, Tomas Carnecky wrote:
> 
>> Should I apply both patches or only the second one (the one that adds 
>> the 'break;')? I applied both and I was still getting the IRQ storms. 
>> This is also on a GM965.
> 
> It shouldn't have mattered. At this point, I'm curious if we're running
> into trouble because of interrupt sharing. We've had good reports from
> people using MSI on GM965, notwithstanding the errata which says they're
> unreliable. It may be that our driver/linux uses them differently enough
> that they work fine. Here's a patch which re-enables MSI for 965GM. Use
> this in place of the other two patches and let us know if it works. In
> other words, revert back to anholt/for-airlied and apply this patch:

This seems to work. At least up to now, i had no issue that i could
blame on MSI.

As for the interrupt sharing: Iirc i could reproduce the irq storm with
only the graphics irq on irq 16, by rmmod'ing uhci_hcd, which normally
shares that irq on this machine.

Regards,
  Pierre