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Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity for HyperV

From Thomas Gleixner <tglx@linutronix.de>
Newsgroups linux.kernel
Subject Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity for HyperV
Date 2015-08-20 13:20 +0200
Message-ID <pZw2Z-3ei-3@gated-at.bofh.it> (permalink)
References (6 earlier) <pZ74B-C4-1@gated-at.bofh.it> <pZ7ej-Nx-35@gated-at.bofh.it> <pZrmF-4VL-1@gated-at.bofh.it> <pZuaS-wx-25@gated-at.bofh.it> <pZuud-TI-5@gated-at.bofh.it>
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On Thu, 20 Aug 2015, Jiang Liu wrote:
> On 2015/8/20 17:15, Thomas Gleixner wrote:
> > On Thu, 20 Aug 2015, Jiang Liu wrote:
> >> 	When converting to hierarchical irqdomain, the IOAPIC
> >> internal and interfaces have changed much, and seems no easy
> >> way to revert cd68f6bd53cf. There may be three possible solutions
> >> here:
> >> 1) use quirk to correct SCI polarity, as the patch does.
> >> 2) change IOAPIC interfaces to provide a special way to
> >>    handle SCI interrupt.
> >> 3) change drivers/acpi/pci_link.c to penalize SCI IRQ so it
> >>    won't be used for PCI IRQ if SCI polarity conflicts with
> >>    PCI IRQ polarity.
> > 
> > Stupid question. Is the SCI polarity ever the opposite of PCI
> > polarity? I.e. is such a ACPI override valid at all? 
> Hi Thomas,
> 	I have analyzed another system which works:
> 1) SCI(IRQ9) works in level, high mode (so such an ACPI override is valid)
> 2) there's a flag to detect whether system works in PIC or APIC mode.
> 3) IRQ9 may be used for PCI IRQ if system works in PIC mode.

Why?

> 4) IRQ9 won't be used for PCI IRQ if system works in APIC mode.
> Based on the above observation, I feel solution 3) may be the best one.

Can you whip up a patch and test it on hyperv and maybe other machines
which have that SCI override.

Thanks

	tglx
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Thread

[Patch v1] x86, ACPI, irq: Fix a regression caused by Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-09 11:00 +0200
  Re: [Patch v1] x86, ACPI, irq: Fix a regression caused by Thomas Gleixner <tglx@linutronix.de> - 2015-08-18 21:40 +0200
    [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity for HyperV Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-19 08:00 +0200
      Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV "Rafael J. Wysocki" <rafael@kernel.org> - 2015-08-19 08:10 +0200
        Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-19 08:30 +0200
          Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV "Rafael J. Wysocki" <rafael@kernel.org> - 2015-08-19 08:50 +0200
            Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-19 09:00 +0200
              Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Thomas Gleixner <tglx@linutronix.de> - 2015-08-19 10:40 +0200
                Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Thomas Gleixner <tglx@linutronix.de> - 2015-08-19 10:50 +0200
                Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-19 11:10 +0200
                Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-20 08:20 +0200
                Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Thomas Gleixner <tglx@linutronix.de> - 2015-08-20 11:20 +0200
                Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-20 11:40 +0200
                Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity  for HyperV Thomas Gleixner <tglx@linutronix.de> - 2015-08-20 13:20 +0200
                [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Jiang Liu <jiang.liu@linux.intel.com> - 2015-08-21 09:40 +0200
                Re: [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Thomas Gleixner <tglx@linutronix.de> - 2015-08-25 10:20 +0200
                Re: [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Aaron Lu <aaron.lu@intel.com> - 2015-08-26 04:50 +0200
                Re: [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Thomas Gleixner <tglx@linutronix.de> - 2015-08-26 10:00 +0200
                Re: [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Thomas Gleixner <tglx@linutronix.de> - 2015-08-26 11:30 +0200
                Re: [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI "Rafael J. Wysocki" <rafael@kernel.org> - 2015-08-26 22:30 +0200
                Re: [Patch v3] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Thomas Gleixner <tglx@linutronix.de> - 2015-08-27 00:10 +0200

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