The sysfs "irq" file contains the legacy INTx IRQ. Or, if the device has
MSI enabled, it contains the first MSI IRQ instead.
Previously this file showed the pci_dev.irq value directly. But we'd
prefer to use pci_dev.irq only for the INTx IRQ and decouple that from any
MSI or MSI-X IRQs.
If the device has MSI enabled, explicitly look up and show the first MSI
IRQ in the sysfs "irq" file. Otherwise, show the INTx IRQ.
This removes the requirement that msi_capability_init() set pci_dev.irq to
the first MSI IRQ when enabling MSI and pci_msi_shutdown() restore the INTx
IRQ when disabling MSI.
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20210825102636.52757-3-21cnbao@gmail.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
ac8e3cef58