linux-toradex.git/drivers/acpi/pci_link.c, branch v4.9.97

ACPI/PCI: pci_link: Include PIRQ_PENALTY_PCI_USING for ISA IRQs

2016-10-24T12:18:14+00:00

Commit 103544d86976 ("ACPI,PCI,IRQ: reduce resource requirements")
replaced the addition of PIRQ_PENALTY_PCI_USING in acpi_pci_link_allocate()
with an addition in acpi_irq_pci_sharing_penalty(), but f7eca374f000
("ACPI,PCI,IRQ: separate ISA penalty calculation") removed the use
of acpi_irq_pci_sharing_penalty() for ISA IRQs.

Therefore, PIRQ_PENALTY_PCI_USING is missing from ISA IRQs used by
interrupt links.  Include that penalty by adding it in the
acpi_pci_link_allocate() path.

Fixes: f7eca374f000 (ACPI,PCI,IRQ: separate ISA penalty calculation)
Signed-off-by: Sinan Kaya 
Acked-by: Bjorn Helgaas 
Tested-by: Jonathan Liu 
Signed-off-by: Rafael J. Wysocki

ACPI/PCI: pci_link: penalize SCI correctly

2016-10-24T12:18:14+00:00

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: 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements)
Link: http://lkml.kernel.org/r/201609251512.05657.linux@rainbow-software.org
Reported-by: Ondrej Zary 
Acked-by: Bjorn Helgaas 
Signed-off-by: Sinan Kaya 
Tested-by: Jonathan Liu 
Signed-off-by: Rafael J. Wysocki

ACPI/PCI/IRQ: assign ISA IRQ directly during early boot stages

2016-10-24T12:18:14+00:00

We do not want to store the SCI penalty in the acpi_isa_irq_penalty[]
table because acpi_isa_irq_penalty[] only holds ISA IRQ penalties and
there's no guarantee that the SCI is an ISA IRQ.  We add in the SCI
penalty as a special case in acpi_irq_get_penalty().

But if we called acpi_penalize_isa_irq() or acpi_irq_penalty_update()
for an SCI that happened to be an ISA IRQ, they stored the SCI
penalty (part of the acpi_irq_get_penalty() return value) in
acpi_isa_irq_penalty[].  Subsequent calls to acpi_irq_get_penalty()
returned a penalty that included *two* SCI penalties.

Fixes: 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements)
Signed-off-by: Sinan Kaya 
Acked-by: Bjorn Helgaas 
Tested-by: Jonathan Liu 
Signed-off-by: Rafael J. Wysocki

ACPI,PCI,IRQ: separate ISA penalty calculation

2016-07-01T23:38:34+00:00

Since commit 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements)
the penalty values are calculated on the fly rather than at boot time.

This works fine for PCI interrupts but not so well for ISA interrupts.

The information on whether or not an ISA interrupt is in use is not
available to the pci_link.c code directly.  That information is
obtained from the outside via acpi_penalize_isa_irq().  [If its
"active" argument is true, then the IRQ is in use by ISA.]

Since the current code relies on PCI Link objects for determination
of penalties, we are factoring in the PCI penalty twice after
acpi_penalize_isa_irq() function is called.

To avoid that, limit the newly added functionality to just PCI
interrupts so that old behavior is still maintained.

Fixes: 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements)
Signed-off-by: Sinan Kaya 
Tested-by: Wim Osterholt 
Signed-off-by: Rafael J. Wysocki

Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()"

2016-07-01T23:38:34+00:00

Trying to make the ISA and PCI init functionality common turned out
to be a bad idea, because the ISA path depends on external
functionality.

Restore the previous behavior and limit the refactoring to PCI
interrupts only.

Fixes: 1fcb6a813c4f "ACPI,PCI,IRQ: remove redundant code in acpi_irq_penalty_init()"
Signed-off-by: Sinan Kaya 
Tested-by: Wim Osterholt 
Signed-off-by: Rafael J. Wysocki

ACPI,PCI,IRQ: factor in PCI possible

2016-07-01T23:38:34+00:00

The change introduced in commit 103544d86976 (ACPI,PCI,IRQ: reduce
resource requirements) omitted the initially applied PCI_POSSIBLE
penalty when the IRQ is active.

Incorrect calculation of the penalty leads the ACPI code to assigning
a wrong interrupt number to a PCI INTx interrupt.

This would not be as bad as it sounds in theory.  It would just cause
the interrupts to be shared and result in performance penalty.

However, some drivers (like the parallel port driver) don't like
interrupt sharing and in the above case they will causes all of
the PCI drivers wanting to share the interrupt to be unable to
request it.

The issue has not been caught in testing because the behavior is
platform-specific and depends on the peripherals ending up sharing
the IRQ and their drivers.

Before the above commit the code would add the PCI_POSSIBLE value
divided by the number of possible IRQ users to the IRQ penalty
during initialization.

Later in that code path, if the IRQ is chosen as the active IRQ or
if it is used by ISA; additional penalties are added.

Fixes: 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements)
Signed-off-by: Sinan Kaya 
Tested-by: Wim Osterholt 
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki

ACPI,PCI,IRQ: correct operator precedence

2016-06-30T13:35:27+00:00

The omitted parenthesis prevents the addition operation when
acpi_penalize_isa_irq function is called.

Fixes: 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements)
Signed-off-by: Sinan Kaya 
Signed-off-by: Rafael J. Wysocki

ACPI,PCI,IRQ: remove SCI penalize function

2016-05-04T23:10:32+00:00

Removing the SCI penalize function as the penalty is now calculated on the
fly.

Signed-off-by: Sinan Kaya 
Acked-by: Bjorn Helgaas 
Signed-off-by: Rafael J. Wysocki

ACPI,PCI,IRQ: remove redundant code in acpi_irq_penalty_init()

2016-05-04T23:10:32+00:00

acpi_irq_get_penalty is now calculating the penalty on the fly now.
No need to maintain global list of penalties or calculate them
at the init time. Removing duplicate code in acpi_irq_penalty_init.

Signed-off-by: Sinan Kaya 
Acked-by: Bjorn Helgaas 
Signed-off-by: Rafael J. Wysocki

ACPI,PCI,IRQ: reduce static IRQ array size to 16

2016-05-04T23:10:31+00:00

Now that the supported number of PCI IRQs are no longer capped
with 256, renaming the static array to support ISA IRQs only
and removing the MAX_IRQS constant.

Signed-off-by: Sinan Kaya 
Acked-by: Bjorn Helgaas 
Signed-off-by: Rafael J. Wysocki