For one of my pci device, output of lspci -vvv says pin A routed to 19. but output of lspci -b -vvv gives 255. All the pci devices gives irq 255 in lspci -b -vvv, while for lspci -vvv it gives different numbers. Can anyone please explain this?
When you insert -b in lspci command it will gives you the interrupt number seen by the device. So this interrupt number will be hardware interrupt number. Without -b, it will give you virtual interrupt number. So these both number will be different.