The point of CONFIG_ISA is to only build drivers for ISA add-on cardsok, fine. So I just wonder what the ISA kconfig dependency gets us forOn another point, I noticed SCSI driver AHA152x depends on ISA, but isI'm not sure what you mean here. As far as I can tell, AHA152x is an ISA
not an isa driver - however it does use port IO. Would such dependencies
need to be changed to depend on HAS_IOPORT?
driver in the sense that it is a driver for ISA add-on cards. However, it
is not a 'struct isa_driver' in the sense that AHA1542 is, AHA152x is even
older and uses the linux-2.4 style initialization using a module_init()
function that does the probing.
aha152x. I experimented by removing the kconfig dependency and enabling
for the arm64 (which does not have CONFIG_ISA) std defconfig and it
built fine.
on architectures that can have such slots. For ISA drivers in particular,
we don't want them to be loaded on machines that don't have them
because of the various ways this can cause trouble with hardwired
port and irq numbers.
Correct, but that's not a problem I'm trying to solve at this point. Thehmmm... if some machines under an arch support "native" port IO and someYeah, that sounds the same as what I was thinking. Maybe IOPORT_NATIVEYou can have those on a number of platforms, such as early
could work as a name. I would think that only x86/ia64 would define it.
A concern though is that someone could argue that is a functional
dependency, rather than just a build dependency.
PowerPC CHRP or pSeries systems, a number of MIPS workstations
including recent Loongson machines, and many Alpha platforms.
don't, then if we use a common multi-platform defconfig which defines
HARDCODED_IOPORT, then we still build for platforms without "native"
port IO, which is not ideal.
machines that have those are extremely rare, so almost all configurations
that one would encounter in practice do not suffer from it, and solving it
reliably would be really hard.