Re: [PATCH V3] VIA IRQ quirk behaviour change

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Sun, Sep 10, 2006 at 05:30:18PM -0400, Lee Revell wrote:

> Sorry, all I have is anecdotal evidence.  The scope of the problem isn't
> fully known.  Could be related to vendors implementing ACPI using SMM.
> Vendors are tight lipped about which hardware is affected because it
> understandably annoys users.

I don't know what you really mean by "implementing ACPI" here. Certain 
queries may generate SMM traps, but I haven't seen any event driven code 
paths that do[1]. If you're polling hardware you may generate some 
latency, but I don't think that's any great surprise.

It would be interesting to have a test case under Linux so we could 
attempt to figure out whether it's an actual problem, or just Windows 
doing awkward things.

[1] outside sort of obvious stuff like ripping out a hotswap bay and 
/potentially/ critical battery status to switch on a warning light, but 
if you hit those situations you're probably pretty much dead anyway

-- 
Matthew Garrett | mjg59@srcf.ucam.org