On 8/30/2016 11:51 AM, Duc Dang wrote: > 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 :) > +1 to this too. We don't need to invent some fake API or push stuff to the arch directory. >> -- >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. > -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- 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
