On Fri, Apr 29, 2022 at 03:49:59PM +0200, Niklas Schnelle wrote: > We introduce a new HAS_IOPORT Kconfig option to indicate support for > I/O Port access. In a future patch HAS_IOPORT=n will disable compilation > of the I/O accessor functions inb()/outb() and friends on architectures > which can not meaningfully support legacy I/O spaces such as s390 or > where such support is optional. So you plan to drop inb()/outb() on architectures where I/O port space is optional? So even platforms that have I/O port space may not be able to use it? This feels like a lot of work where the main benefit is to keep Kconfig from offering drivers that aren't of interest on s390. Granted, there may be issues where inb()/outb() does the wrong thing such as dereferencing null pointers when I/O port space isn't implemented. I think that's a defect in inb()/outb() and could be fixed there. Bjorn
