On Tue, Aug 30, 2016 at 3:08 AM, Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote: > On Fri, Aug 26, 2016 at 06:53:29PM -0400, Sinan Kaya wrote: >> >> >> Let me throw option d here. >> >> >> >> I know Bjorn wants to keep ACTIVE_LOW in the code for common code but >> >> can't we override this in an arch specific way (arm64's pci.c) while >> >> creating the root bridge? >> > >> > On what basis ? You were not copied in from the beginning, but that >> > is not different from Duc's initial proposal, which Marc discarded >> > because it should not be done at arch level, it depends on the interrupt >> > controller. >> >> I happen to watch the linux-pci and linux-acpi mail-lists. I also saw >> Duc's initial proposal. >> >> I can't imagine someone building an ACPI compliant ARM64 platform >> without a GIC interrupt controller. >> >> The SBSA spec already mentions what kind of compatibility should be >> maintained with respect to GIC. You can't have an ACPI system that's >> SBSA compliant and not using GIC. >> >> Can't we just hard code this to ACTIVE_HIGH in arch directory if ACPI >> is defined. Why do we have to reach out to the interrupt controller? > > Patch below (horrible but no solution will be shiny either). > >> https://lists.linaro.org/pipermail/linaro-acpi/2015-November/005973.html > > [...] > >> If you look at my email above, I tried getting rid of PCI Link object >> and I couldn't. I sticked to only thing that works. > > That's what I object to. If the ACPI bindings do not work for ARM > we do not work around issues, we upgrade the specs because what may work > for you has to work on all ARM platforms (and all FW developers have > to be aware of that). Granted, this is a tiny snag, but the point is > that no one knows what's the correct way of describing PCI legacy IRQs > on ARM and we need that rectified. > > This does the trick for me (I can turn it into a function/look-up > that returns the polarity), I am sure it will ruffle feathers but > we have to find a solution so here it is (that acpi_irq_model gem > is already used in generic code drivers/acpi/pci_link.c ;-)) > Good catch! This acpi_irq_model gem does help X-Gene :) > -- >8 -- > diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c > index 2c45dd3..c9b8c85 100644 > --- a/drivers/acpi/pci_irq.c > +++ b/drivers/acpi/pci_irq.c > @@ -411,7 +411,8 @@ int acpi_pci_irq_enable(struct pci_dev *dev) > int gsi; > u8 pin; > int triggering = ACPI_LEVEL_SENSITIVE; > - int polarity = ACPI_ACTIVE_LOW; > + int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ? > + ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW; > char *link = NULL; > char link_desc[16]; > int rc; Regards, Duc Dang. -- 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
