On Fri, Jul 1, 2022 at 6:17 PM Pierre Gondois <pierre.gondois@xxxxxxx> wrote: > > From: Pierre Gondois <Pierre.Gondois@xxxxxxx> > > In ACPI 6.4, s6.2.13 "_PRT (PCI Routing Table)", PCI legacy > interrupts can be described though a link device (first model). > From s6.2.16 "_SRS (Set Resource Settings)": > "This optional control method [...]" > > Make it optional to have a _SRS method for link devices. Note that if _DIS is present, _SRS is necessary to enable the link and acpi_pci_link_add() evaluates _DIS for all links. So you need to check both, not just one. Moreover, it doesn't make much sense to provide _PRS without _SRS and arguably _PRS is needed if _SRS is present, so this needs to be taken into account too. AFAICS, the only valid configuration in which _SRS and _PRS are not present is when _DIS is not present too, so only _CRS is present and the IRQ listed by it is actually in use. However, in that case it is hardly necessary to add a device object for the PCI link device at all. > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215560 > Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx> > --- > drivers/acpi/pci_link.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c > index 58647051c948..129e3e7e80ee 100644 > --- a/drivers/acpi/pci_link.c > +++ b/drivers/acpi/pci_link.c > @@ -288,6 +288,13 @@ static int acpi_pci_link_set(struct acpi_pci_link *link, int irq) > if (!irq) > return -EINVAL; > > + if (!acpi_has_method(handle, METHOD_NAME__SRS)) { > + if (link->irq.active == irq) > + return 0; > + acpi_handle_err(handle, "Unable to set IRQ %d: No _SRS.\n", irq); > + return -ENODEV; > + } > + > resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL); > if (!resource) > return -ENOMEM; > -- > 2.25.1 >
