Greetings, I've got a miniPCIe card with a TW6869 8x frame grabber that stopped working on an IMX6 based board with a PLX switch with Linux 4.17 as the driver errors out with 'tw686x 0000:07:00.0: unable to request interrupt' (request_irq() fails). I've found this only happens on boards that have a switch. Note I'm booting with pci=nomsi as well as the IMX6 has a limitation where legacy IRQ's wont fire if MSI irq's are enabled. Strangely I don't see this issue with other cards such as the ath9k with msi disabled. I bisected the issue to 7c5925afbc58c6d6b384e1dc051bb992969bf787 'PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API' which due to continued changes in drivers/pci/dwc can no longer be reverted. Any ideas what happened here? IMX6 PCIe through a bridge always seems not so well tested and very fragile over the past couple of years. Best Regards, Tim
