Re: [ACPI] [PATCH] PCI IRQ resource deallocation support [2/3]

From: Kenji Kaneshige
Date: Fri Sep 24 2004 - 01:40:21 EST


Hi Takayoshi,

Thank you for feedback.

Takayoshi Kochi wrote:
> Why do we need to fiddle with dev->irq? I think it should
> just be undefined after acpi_pci_irq_disable().

I had been considering what the "undefined dev->irq" was.
In fact, I had other ideas that was clearing it by zero or
-1 (0xffffffff). But I didn't know if we can use these values
as a undefined IRQ number. So I'm clearing it by the value
which was assigned by PCI core code (pci_read_irq()) before
acpi_pci_irq_enable() was called.

I think it has little sense in restoring value from the configuration
space to dev->irq or clearing it.

If we do preventive programming, it may be worth
trying to define some magic constant (e.g. PCI_UNDEFINED_IRQ) and
panic/BUG when the irq is being enabled.
Otherwise, leaving dev->irq as it is would be ok.

Hmm, I think you are right.
I'll change my patch to leave dev->irq as it is. And then I'll
investigate about defining PCI_UNDEFINED_IRQ.

In fact, I posted updated patches a little before. I'll re-post
it with your feedback :-)

Thanks,
Kenji Kaneshige

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