Some devices use 255 as default value of Interrupt Line register, and this
maybe causes pdev->irq is set as IRQ_NOTCONNECTED in some scenarios. For
example, NVMe controller connects to Intel Volume Management Device (VMD).
In this situation, IRQ_NOTCONNECTED means INTx line is not connected, not
fault. If bind uio_pci_generic to these devices, uio frame will return
-ENOTCONN through request_irq.

This patch allows binding uio_pci_generic to device with dev->irq of
IRQ_NOTCONNECTED.
Acked-by: Kyungsan Kim <ks0204.kim@samsung.com>
Signed-off-by: Jie Li <jie6.li@samsung.com>
Link: https://lore.kernel.org/r/1612153559-17028-1-git-send-email-jie6.li@samsung.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>