From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sat, 22 Oct 2016 18:58:37 -0500 From: Bjorn Helgaas To: Sinan Kaya Cc: linux-acpi@vger.kernel.org, rjw@rjwysocki.net, bhelgaas@google.com, ravikanth.nalla@hpe.com, linux@rainbow-software.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, alex.williamson@redhat.com, linux-pci@vger.kernel.org, agross@codeaurora.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, wim@djo.tudelft.nl, linux-arm-kernel@lists.infradead.org, Len Brown Subject: Re: [PATCH V3 1/3] ACPI, PCI IRQ: add PCI_USING penalty for ISA interrupts Message-ID: <20161022235837.GA1668@localhost> References: <1476505867-24599-1-git-send-email-okaya@codeaurora.org> <1476505867-24599-2-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1476505867-24599-2-git-send-email-okaya@codeaurora.org> Sender: linux-acpi-owner@vger.kernel.org List-ID: On Sat, Oct 15, 2016 at 12:31:05AM -0400, Sinan Kaya 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. > > 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. > > We need to add the PCI_USING penalty for ISA interrupts too if the link is > in use and matches our ISA IRQ number. I think the history about the array size is more than is necessary for this changelog. I think the useful part is something like this: ACPI: pci_link: Include PIRQ_PENALTY_PCI_USING for ISA IRQs 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 > --- > 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; > + > printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n", > acpi_device_name(link->device), > acpi_device_bid(link->device), link->irq.active); > -- > 1.9.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel