From: Barry Song <song.bao.hua@xxxxxxxxxxxxx> /sys/bus/pci/devices/.../irq has been there for many years but it has never been documented. This patch is trying to document it. Plus, irq ABI is very confusing at this moment especially for MSI and MSI-x cases. MSI sets irq to the first number in the vector, but MSI-X does nothing for this though it saves default_irq in msix_setup_entries(). Weird the saved default_irq for MSI-X is never used in pci_msix_shutdown(), which is quite different with pci_msi_shutdown(). Thus, this patch also moves to show the first IRQ number which is from the first msi_entry for MSI-X. Hopefully, this can make irq ABI more clear and more consistent. -v2: - split into two patches according to Bjorn's comments; - Add Greg's Acked-by, thanks for reviewing! -v1: https://lore.kernel.org/lkml/20210813122650.25764-1-21cnbao@xxxxxxxxx/#t Barry Song (2): PCI/MSI: Fix the confusing IRQ sysfs ABI for MSI-X Documentation: ABI: sysfs-bus-pci: Add description for IRQ entry Documentation/ABI/testing/sysfs-bus-pci | 8 ++++++++ drivers/pci/msi.c | 6 ++++++ 2 files changed, 14 insertions(+) -- 1.8.3.1