On 24.12.2017 23:42, William Breathitt Gray wrote: (..) > By the way, don't hesitate to ask for more information on the ISA > subsystem -- a lot of maintainers are unaware that it even exists since > so few devices nowadays use ISA-style communication -- but I'm always > happy to help. :) It turns out that all this ISA bus is behind CONFIG_ISA_BUS_API which cannot be automatically selected by this driver due to a recursive dependency conflict with CONFIG_STX104. All the existing ISA bus drivers seem to depend on CONFIG_ISA_BUS_API instead of selecting it but IMHO this is wrong because: 1) This Kconfig option doesn't really enable or disable any bus support but building of a library of some common boilerplate code. Libraries are normally selected by drivers needing them and only provided as an user-selectable option if there is a possibility that a out-of-tree module would need it, 2) On x86_64 this option (or rather, its parent option CONFIG_ISA_BUS) cannot be enabled without CONFIG_EXPERT, 3) This device isn't really a ISA bus device any more than, for example, a 8250 serial port or a PC-style parallel port and these don't need that an user explicitly enables "ISA bus support" in his kernel configuration. To be clear I'm fine with converting this driver to use the ISA bus (in fact, I have already done so), but I think that currently this would be a regression from user-friendliness perspective due to the points above. > William Breathitt Gray Best regards, Maciej Szmigiero -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html