Re: [PATCH/RFC 2/2]ACPI PNP driver

[Bjorn Helgaas <bjorn.helgaas-VXdhtT5mjnY@public.gmane.org>]

On Wednesday 22 September 2004 8:41 pm, Li Shaohua wrote:
> On Thu, 2004-09-23 at 02:52, Bjorn Helgaas wrote:
> > On Tuesday 21 September 2004 10:35 pm, Li Shaohua wrote:
> > > +#define valid_IRQ(i) (((i) != 0) && ((i) != 2) && ((i) < 16))
> > > ...
> > > + case ACPI_RSTYPE_IRQ:
> > > +  if ((res->data.irq.number_of_interrupts > 0) &&
> > > +   valid_IRQ(res->data.irq.interrupts[0])) {
> > 
> > Why the valid_IRQ() check?  It certainly doesn't make any sense
> > on ia64.
> I checked the IA32 systems and Tiger4, and I haven't saw any PNP device
> with irq >= 16. I don't know the HP specific system, could you please
> show me a light?

res->data.irq.interrupts[0] is an ACPI GSI.  I'm not aware of
anything in the spec that prevents use of an arbitrary 32-bit
value.  For example, the HP rx2600 and zx6000 use the following
values for built-in serial ports:

 rx2600: GSI 34 (edge, high) -> CPU 0 (0x0000) vector 49
 rx2600: ttyS0 at MMIO 0xff5e0000 (irq = 49) is a 16550A
 rx2600: GSI 35 (edge, high) -> CPU 1 (0x0100) vector 59
 rx2600: ttyS1 at MMIO 0xff5e2000 (irq = 59) is a 16550A

 zx6000: GSI 45 (edge, high) -> CPU 0 (0x0000) vector 49
 zx6000: ttyS0 at MMIO 0xff5e0000 (irq = 49) is a 16550A
 zx6000: GSI 46 (edge, high) -> CPU 0 (0x0000) vector 50
 zx6000: ttyS1 at MMIO 0xff5e2000 (irq = 50) is a 16550A

> > It feels like a potential bug that we populate the pnp_irq map
> > with all the interrupts, but we only acpi_register_gsi() the
> > first one.
> It doesn't matter. A device only uses one IRQ. pnp_irq map presents the
> possible IRQs for device if it needs dynamically configure.

Oh, I see.  Then it sounds like we need places to unregister the
old GSI and register the new one if the configuration is dynamically
changed.


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