| Message ID | 1454606941-9523-23-git-send-email-tn@semihalf.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Feb 04, 2016 at 06:29:00PM +0100, Tomasz Nowicki wrote: > This is the last step before enabling generic ACPI PCI host controller > for ARM64. We need to take care of legacy IRQ mapping for non-MSI(X) > PCI devices. pcibios_enable_device() boot order is not sensitive to > ACPI device enumeration, so it is the best place to assign device's IRQs. I guess you are referring to: https://lists.linaro.org/pipermail/linaro-acpi/2015-October/005944.html It is weird that the dependency can't be enforced, I will have a look into this, it would be nice to have DT and ACPI legacy IRQs mapping confined in pcibios_add_device() so that we can remove them in one go when Matthew's series is merged. As for the MSI check, by reading commit history its need I think it harks back to bba6f6fc, which was supposed to be a quick hack and it has been in the kernel for 9 years :), is it really needed ? > NOTE: *This is going to be temporary solution*. There is ongoing work > which aims for cleaning legacy IRQ allocation, see [1]. > We can consider this patch as the necessary evil which will be removed > once [1] series hits mailnline in the near future. > > 1. http://comments.gmane.org/gmane.linux.kernel.pci/46461 > > Signed-off-by: Tomasz Nowicki <tn@semihalf.com> > --- > arch/arm64/kernel/pci.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c > index 023b983..d1a701f 100644 > --- a/arch/arm64/kernel/pci.c > +++ b/arch/arm64/kernel/pci.c > @@ -39,16 +39,26 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, > } > > /** > - * pcibios_enable_device - Enable I/O and memory. > + * pcibios_enable_device - Enable I/O, memory and legacy IRQs for ACPI. > * @dev: PCI device to be enabled > * @mask: bitmask of BARs to enable > */ > int pcibios_enable_device(struct pci_dev *dev, int mask) > { > + int ret; > + > if (pci_has_flag(PCI_PROBE_ONLY)) > return 0; > > - return pci_enable_resources(dev, mask); > + ret = pci_enable_resources(dev, mask); > + if (ret < 0) > + return ret; > + > +#ifdef CONFIG_ACPI > + if (!pci_dev_msi_enabled(dev)) > + return acpi_pci_irq_enable(dev); You need a guard here anyway, we do not want to probe ACPI IRQ if it is disabled (ie acpi_pci_disabled). Same goes for DT in pcibios_add_device(), which is not making this code any nicer. Lorenzo > +#endif > + return 0; > } > > /* > -- > 1.9.1 >
On 11.02.2016 12:58, Lorenzo Pieralisi wrote: > As for the MSI check, by reading commit history its need I think > it harks back to bba6f6fc, which was supposed to be a quick hack and it > has been in the kernel for 9 years:), is it really needed ? IMO, yes it is needed. We need to chose MSI vs IRQ, and MSI is preferable option. Tomasz
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index 023b983..d1a701f 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -39,16 +39,26 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, } /** - * pcibios_enable_device - Enable I/O and memory. + * pcibios_enable_device - Enable I/O, memory and legacy IRQs for ACPI. * @dev: PCI device to be enabled * @mask: bitmask of BARs to enable */ int pcibios_enable_device(struct pci_dev *dev, int mask) { + int ret; + if (pci_has_flag(PCI_PROBE_ONLY)) return 0; - return pci_enable_resources(dev, mask); + ret = pci_enable_resources(dev, mask); + if (ret < 0) + return ret; + +#ifdef CONFIG_ACPI + if (!pci_dev_msi_enabled(dev)) + return acpi_pci_irq_enable(dev); +#endif + return 0; } /*
This is the last step before enabling generic ACPI PCI host controller for ARM64. We need to take care of legacy IRQ mapping for non-MSI(X) PCI devices. pcibios_enable_device() boot order is not sensitive to ACPI device enumeration, so it is the best place to assign device's IRQs. NOTE: *This is going to be temporary solution*. There is ongoing work which aims for cleaning legacy IRQ allocation, see [1]. We can consider this patch as the necessary evil which will be removed once [1] series hits mailnline in the near future. 1. http://comments.gmane.org/gmane.linux.kernel.pci/46461 Signed-off-by: Tomasz Nowicki <tn@semihalf.com> --- arch/arm64/kernel/pci.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)