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. V3: * 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: add PCI_USING penalty for ISA interrupts Revert "ACPI,PCI,IRQ: remove SCI penalize function" ACPI,PCI,IRQ: correct SCI penalty calculation arch/x86/kernel/acpi/boot.c | 1 + drivers/acpi/pci_link.c | 34 +++++++++++++++++++--------------- include/linux/acpi.h | 1 + 3 files changed, 21 insertions(+), 15 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
