Re: ACPI ignoring IRQ flags in PRT

[Matthew Wilcox <willy-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org>]

On Sun, Jul 13, 2003 at 02:52:38PM +0100, Andrew de Quincey wrote:
> 
> Hi, from my understanding of the ACPI spec, each IRQ as specified in the _PRT 
> has additional flags associated with it (e.g. specifying the polarity, level 
> etc) that should be used for this IRQ. 
> 
> The Linux ACPI code seems to be ignoring these, and hardcodes them to the 
> values that cause problems for me. Is there a reason, or has that code just 
> not been written yet?

you can't mean the _PRT.  the _PRT describes PCI interrupts, and those
have their polarity and trigger specified by the PCI spec.  i suspect you
mean someting else, but i'm not sure what.  can't be the SCI interrupt
since that's defined to be level, low, sharable.

some of the ia64 acpi code pays attention to polarity and edge vs level.
now that we know this is an issue on x86, maybe some more people will be
interested in thinking about how to fix this properly.  here's what we
currently have on ia64:

int acpi_register_irq (u32 gsi, u32 polarity, u32 trigger);

-- 
"It's not Hollywood.  War is real, war is primarily not about defeat or
victory, it is about death.  I've seen thousands and thousands of dead bodies.
Do you think I want to have an academic debate on this subject?" -- Robert Fisk


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