Hi Rafael, On 10/15/2016 8:39 AM, Rafael J. Wysocki wrote: > On Sat, Oct 15, 2016 at 6:31 AM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote: >> The change introduced in commit 103544d86976 ("ACPI,PCI,IRQ: reduce >> resource requirements") removed PCI_USING penalty from >> acpi_pci_link_allocate function as there is no longer a fixed size penalty >> array for both PCI interrupts greater than 16. >> >> The array size has been reduced to 16 and array name got prefixed as ISA >> since it only is accountable for the ISA interrupts. >> >> The original change in commit 103544d86976 ("ACPI,PCI,IRQ: reduce >> resource requirements") removed penalty assignment in the code for PCI >> thinking that we will add the penalty later in acpi_irq_pci_sharing_penalty >> function. > > I'd write the above this way: > > "Commit 103544d86976 (ACPI,PCI,IRQ: reduce resource requirements) > dropped the PCI_USING penalty from acpi_pci_link_allocate() with the > assumption that the penalty will be added later in > acpi_irq_pci_sharing_penalty()." > > This conveys essentially the same information (up to some irrelevant > bits), but in a clearer way IMO. > >> >> However, this function only gets called if the IRQ number is greater than >> 16 and acpi_irq_get_penalty function gets called before ACPI start in >> acpi_isa_irq_available and acpi_penalize_isa_irq functions. We can't rely >> on iterating the link list. > > "However, acpi_irq_pci_sharing_penalty() is only called for IRQ > numbers above 15. Moreover, acpi_irq_get_penalty() is invoked by > acpi_isa_irq_available() and acpi_penalize_isa_irq() before the ACPI > initialization and the PCI interrupt links list is not ready at that > point, so it cannot be relied on when computing the penalty." > >> >> We need to add the PCI_USING penalty for ISA interrupts too if the link is >> in use and matches our ISA IRQ number. > > "For this reason, the PCI_USING penalty has to be added in > acpi_pci_link_allocate() directly if the link has been enabled > successfully and the IRQ number is within the ISA range." > > IIUC > >> >> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx> >> --- >> drivers/acpi/pci_link.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c >> index c983bf7..a212709 100644 >> --- a/drivers/acpi/pci_link.c >> +++ b/drivers/acpi/pci_link.c >> @@ -619,6 +619,10 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link) >> acpi_device_bid(link->device)); >> return -ENODEV; >> } else { >> + if (link->irq.active < ACPI_MAX_ISA_IRQS) >> + acpi_isa_irq_penalty[link->irq.active] += >> + PIRQ_PENALTY_PCI_USING; >> + > > There's no need to break the line here and I would put the above after > the printk(). > > Or even after the whole "else" branch (which is unnecessary, but let's > limit changes in this patch). > >> printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n", >> acpi_device_name(link->device), >> acpi_device_bid(link->device), link->irq.active); >> -- > Thanks for the feedback. I can resubmit with the comments corrected. I'll wait until I hear from Bjorn first. > Thanks, > Rafael > -- 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-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html