Re: [PATCH V7] ACPI, PCI, irq: support IRQ numbers greater than 256

From: Sinan Kaya
Date: Tue Dec 01 2015 - 11:30:29 EST


On 12/1/2015 10:30 AM, Bjorn Helgaas wrote:
> Not sure whether you saw my earlier response about this:
>
Sorry, I missed it.

> ACPI_MAX_IRQS is only used to size the acpi_irq_penalty[] table (and
> after your patch, to validate IRQ numbers from ACPI). But I think
> the acpi_irq_penalty[] table is a design we've outgrown. I *think*
> we only care about penalties for IRQs 0-15, so even a 256-entry
> table is more than we need.
>
> If we could make acpi_irq_penalty[] a fixed size of 16 entries or
> replace it with a linked list, I think we could get rid of
> ACPI_MAX_IRQS completely. Then the validation checks you add below
> would be unnecessary and we could handle any interrupt number
> supplied from ACPI.
>
> I think it would be really nice to get rid of the arbitrary maximum
> interrupt ID (1020).

Let me look and do some testing. I'll try to do less damage by using a
link list rather than 16 and try to replicate the existing functionality.

--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project
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