interrupts run crazy on 2.6.28+

[Kyle McMartin]

On Thu, Jan 22, 2009 at 07:15:05PM -0500, Chuck Anderson wrote:
> My Lenovo T61 occasionally goes crazy with interrupts under kernels >= 
> 2.6.28.  powertop shows the situation clearly:
> 
> Top causes for wakeups:
>   99.4% (64644.0)       <interrupt> : ahci, uhci_hcd:usb5, yenta, 
> i915 at pci:0000:00:02.0 
> 
> How does one tell which device is causing all these interrupts?
> 

Short answer: you can't. We don't currently log which irq handler
successfully handled an interrupt (since on a shared line, we poke each
one in sequence until they're all tried (since we can't know which
devices actually raised the irq.))

Long answer: I testbuilt a patch but don't feel like rebooting any of my
machines to see if it works. Poke me privately if you want to rebuild
your kernel and try it.

regards, Kyle