Re: [PATCH V5 0/3] ACPI,PCI,IRQ: revert penalty calculation for ISA and SCI interrupts

["Rafael J. Wysocki" <rafael@kernel.org>]

On Mon, Oct 24, 2016 at 6:31 AM, Sinan Kaya <okaya@codeaurora.org> wrote:
>
> By the time ACPI gets initialized, this code tries to determine an
> IRQ number based on penalty values in this array. It will try to locate
> the IRQ with the least penalty assignment so that interrupt sharing is
> avoided if possible.
>
> A couple of notes about the external APIs:
> 1. These API can be called before the ACPI is started. Therefore, one
> cannot assume that the PCI link objects are initialized for calculating
> penalties.
> 2. The polarity and trigger information passed via the
> acpi_penalize_sci_irq from the BIOS may not match what the IRQ subsystem
> is reporting as the call might have been placed before the IRQ is
> registered by the interrupt subsystem.
>
> The reverted changes were in the direction to remove these external API and
> try to calculate the penalties at runtime for the ISA, SCI as well as PCI
> IRQS.
> This didn't work out well with the existing platforms.
>
> V5:
> * clean up the commit message for 1/3 and 2/3
> * drop 3/3
> * bring back ACPI, PCI IRQ: add PCI_USING penalty for ISA interrupts as 3/3
>
> V4:
> https://www.spinics.net/lists/arm-kernel/msg537158.html
> * Drop ACPI, PCI IRQ: add PCI_USING penalty for ISA interrupts
> * A new patch to isolate early boot ISA penalty calculations from dynamic
> penalty calculation by directly modifying the array members in
> ("ACPI, PCI, IRQ: assign ISA IRQ directly during early boot stages")
> * Now that we isolated both SCI and ISA interrupts, revert commit ("Revert
> "ACPI,PCI,IRQ: separate ISA penalty calculation"") and commit
> ("487cf917ed0d
> (Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()")
> to share code between ISA and PCI penalties as originally intended.
>
> V3:
> http://www.spinics.net/lists/arm-kernel/msg536208.html
> * drop patch #1 as discussed with Bjorn
> * add patch #3 to track SCI irq and penalty separately
>
> V2: https://lkml.org/lkml/2016/10/1/106
> * Commit message updates
>
> V1:
> http://lists-archives.com/linux-kernel/28673954-revert-acpi-pci-irq-reduce-static-irq-array-size-to-16.html
> * initial implementation
>
> Sinan Kaya (3):
>   ACPI, PCI, IRQ: assign ISA IRQ directly during early boot stages
>   ACPI: pci_link: penalize SCI correctly
>   ACPI: pci_link: Include PIRQ_PENALTY_PCI_USING for ISA IRQs
>
>  arch/x86/kernel/acpi/boot.c |  1 +
>  drivers/acpi/pci_link.c     | 38 +++++++++++++++++++++-----------------
>  include/linux/acpi.h        |  1 +
>  3 files changed, 23 insertions(+), 17 deletions(-)

I've queued up this series for the next ACPI pull request with 4.9 fixes.

Thanks,
Rafael