On Mon, Oct 23, 2023 at 12:25:18PM +0300, Ilpo Järvinen wrote: > On Wed, 18 Oct 2023, Crescent CY Hsieh wrote: > > + /* > > + * RS232 is not supported for MOXA PCIe boards with device IDs > > + * matching the pattern 0x*3**. > > + */ > > + if (pci_moxa_match_second_digit(device, 0x0300)) > > + return -EOPNOTSUPP; > > This is not the correct error code I think. Maybe return -ENXIO instead. I think EOPNOTSUPP or ENOTSUPP would be more reasonable, they directly indicates "operation is not supported". However, EOPNOTSUPP is used for network-related and ENOTSUPP is used for NFSv3 protocol, even though they are already been used throughout the kernel. Maybe add a new one stand for serial, or clean them up into a general one, or use EOPNOTSUPP and ENOTSUPP just for now? --- Sincerely, Crescent CY Hsieh
