Em Mon, 27 Dec 2021 17:42:47 +0100 Niklas Schnelle <schnelle@xxxxxxxxxxxxx> escreveu: > We introduce a new HAS_IOPORT Kconfig option to gate 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. On these platforms > inb()/outb() etc are currently just stubs in asm-generic/io.h which when > called will cause a NULL pointer access which some compilers actually > detect and warn about. > > The dependencies on HAS_IOPORT in drivers as well as ifdefs for > HAS_IOPORT specific sections will be added in subsequent patches on > a per subsystem basis. Then a final patch will ifdef the I/O access > functions on HAS_IOPORT thus turning any use not gated by HAS_IOPORT > into a compile-time warning. > > Link: https://lore.kernel.org/lkml/CAHk-=wg80je=K7madF4e7WrRNp37e3qh6y10Svhdc7O8SZ_-8g@xxxxxxxxxxxxxx/ > Co-developed-by: Arnd Bergmann <arnd@xxxxxxxxxx> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxxxx> > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> ... > @@ -486,6 +487,9 @@ config HAS_IOMEM > depends on !NO_IOMEM > default y > > +config HAS_IOPORT > + def_bool ISA || LEGACY_PCI > + That doesn't sound right. The only dependency for LEGACY_PCI is PCI. If one selects LEGACY_PCI on an architecture that doesn't support it, this will cause problems. Instead, HAS_IOPORT should be selected at architecture level, and the dependency here should be just the opposite: LEGACY_API should depends on HAS_IOPORT. Thanks, Mauro
