Commit f1caa61d authored by Sinan Kaya's avatar Sinan Kaya Committed by Rafael J. Wysocki
Browse files

ACPI/PCI: pci_link: penalize SCI correctly 

Ondrej reported that IRQs stopped working in v4.7 on several
platforms.  A typical scenario, from Ondrej's VT82C694X/694X, is:

ACPI: Using PIC for interrupt routing
ACPI: PCI Interrupt Link [LNKA] (IRQs 1 3 4 5 6 7 10 *11 12 14 15)
ACPI: No IRQ available for PCI Interrupt Link [LNKA]
8139too 0000:00:0f.0: PCI INT A: no GSI

We're using PIC routing, so acpi_irq_balance == 0, and LNKA is already
active at IRQ 11. In that case, acpi_pci_link_allocate() only tries
to use the active IRQ (IRQ 11) which also happens to be the SCI.

We should penalize the SCI by PIRQ_PENALTY_PCI_USING, but
irq_get_trigger_type(11) returns something other than
IRQ_TYPE_LEVEL_LOW, so we penalize it by PIRQ_PENALTY_ISA_ALWAYS
instead, which makes acpi_pci_link_allocate() assume the IRQ isn't
available and give up.

Add acpi_penalize_sci_irq() so platforms can tell us the SCI IRQ,
trigger, and polarity directly and we don't have to depend on
irq_get_trigger_type().

Fixes: 103544d8 (ACPI,PCI,IRQ: reduce resource requirements)
Link: http://lkml.kernel.org/r/201609251512.05657.linux@rainbow-software.org


Reported-by: default avatarOndrej Zary <linux@rainbow-software.org>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarSinan Kaya <okaya@codeaurora.org>
Tested-by: default avatarJonathan Liu <net147@gmail.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent eeaed4bb

arch/x86/kernel/acpi/boot.c

+1 −0
Original line number Diff line number Diff line
@@ -454,6 +454,7 @@ static void __init acpi_sci_ioapic_setup(u8 bus_irq, u16 polarity, u16 trigger, 
		polarity = acpi_sci_flags & ACPI_MADT_POLARITY_MASK;



	mp_override_legacy_irq(bus_irq, polarity, trigger, gsi);

	acpi_penalize_sci_irq(bus_irq, trigger, polarity);



	/*

	 * stash over-ride to indicate we've been here

drivers/acpi/pci_link.c

+15 −15
Original line number Diff line number Diff line
@@ -87,6 +87,7 @@ struct acpi_pci_link { 


static LIST_HEAD(acpi_link_list);

static DEFINE_MUTEX(acpi_link_lock);

static int sci_irq = -1, sci_penalty;



/* --------------------------------------------------------------------------

                            PCI Link Device Management
@@ -496,25 +497,13 @@ static int acpi_irq_get_penalty(int irq) 
{

	int penalty = 0;



	/*

	* Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict

	* with PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be

	* use for PCI IRQs.

	*/

	if (irq == acpi_gbl_FADT.sci_interrupt) {

		u32 type = irq_get_trigger_type(irq) & IRQ_TYPE_SENSE_MASK;



		if (type != IRQ_TYPE_LEVEL_LOW)

			penalty += PIRQ_PENALTY_ISA_ALWAYS;

		else

			penalty += PIRQ_PENALTY_PCI_USING;

	}

	if (irq == sci_irq)

		penalty += sci_penalty;



	if (irq < ACPI_MAX_ISA_IRQS)

		return penalty + acpi_isa_irq_penalty[irq];



	penalty += acpi_irq_pci_sharing_penalty(irq);

	return penalty;

	return penalty + acpi_irq_pci_sharing_penalty(irq);

}



int __init acpi_irq_penalty_init(void)
@@ -881,6 +870,17 @@ bool acpi_isa_irq_available(int irq) 
		    acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);

}



void acpi_penalize_sci_irq(int irq, int trigger, int polarity)

{

	sci_irq = irq;



	if (trigger == ACPI_MADT_TRIGGER_LEVEL &&

	    polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)

		sci_penalty = PIRQ_PENALTY_PCI_USING;

	else

		sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;

}



/*

 * Over-ride default table to reserve additional IRQs for use by ISA

 * e.g. acpi_irq_isa=5

include/linux/acpi.h

+1 −0
Original line number Diff line number Diff line
@@ -326,6 +326,7 @@ struct pci_dev; 
int acpi_pci_irq_enable (struct pci_dev *dev);

void acpi_penalize_isa_irq(int irq, int active);

bool acpi_isa_irq_available(int irq);

void acpi_penalize_sci_irq(int irq, int trigger, int polarity);

void acpi_pci_irq_disable (struct pci_dev *dev);



extern int ec_read(u8 addr, u8 *val);

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