[+cc Rob, beginning of thread https://lore.kernel.org/r/20210514080025.1828197-5-chenhuacai@xxxxxxxxxxx] On Sat, May 15, 2021 at 11:52:53AM +0800, Huacai Chen wrote: > On Fri, May 14, 2021 at 10:52 PM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote: > > 在 2021/5/14 16:00, Huacai Chen 写道: > > > From: Jianmin Lv <lvjianmin@xxxxxxxxxxx> > > > > > > In LS7A, multifunction device use same pci PIN and different > > > irq for different function, so fix it for standard pci PIN > > > usage. > > > > Hmm, I'm unsure about this change. > > The PCIe port, or PCI-to-PCI bridge on LS7A only have a single > > upstream interrupt specified in DeviceTree, how can this quirk > > work? > > LS7A will be shared by MIPS-based Loongson and LoongArch-based > Loongson, LoongArch use ACPI rather than FDT, so this quirk is needed. Can you expand on this a little bit? Which DT binding are you referring to? Is it in the Linux source tree? I think Linux reads Interrupt Pin for both FDT and ACPI systems, and apparently that register contains the same value for all functions of this multi-function device. The quirk will be applied for both FDT and ACPI systems, but it sounds like you're saying this is needed *because* LoongArch uses ACPI. Bjorn
