Re: [patch] s390 kconfig cleanup.

[Andi Kleen <ak@suse.de>]

On Monday 15 May 2006 19:16, Martin Schwidefsky wrote:
> Hi folks,
> I tried once again to clean up the Kconfig files for s390.
> We do not use drivers/Kconfig so far because this creates
> a lot of config options that make absolutely no sense for
> s390. The hardware for whole families of drivers, e.g.
> IPMI, TPM, I2C, I2O, ATA, IEEE1394, ISDN, etc, do not exist
> and very likely will never exist on a s390.
> 
> The "solution" so far had been to avoid drivers/Kconfig and
> use a special s390 version in driver/s390/Kconfig which
> includes some Kconfig files from the drivers directory
> tree and <copies> a few more config options which are useful
> for s390.
> 
> This has obviously two drawbacks: 1) we tend to "forget" new
> useful config options from Kconfig files we do not include,
> 2) the copies of the config options bit-rot just like code
> does, for example we still have UNIX98_PTY_COUNT which does
> not exist anymore.
> 
> The attached patch makes s390 use the common drivers/Kconfig
> and adds a lot of "depends on !S390" to hide all the config
> options that do not make sense for us.> What I think could 
> be improved is the fact that the dependency is negative,
> that is not-something, it would be much cleaner to have
> positive dependencies. For example the menues for Fusion
> or I2O are hidden with "depends on PCI" which is much nicer
> than "depends on !S390". Unluckily it is not obvious what
> the positive dependency should be for almost all menus.
> That is where the arch people get involved. Can we come
> up with a method how to "tag" all menus in the Kconfig files
> under drivers/ with a positive list of the architectures
> that actually want to include the menu/driver? Or even
> better tag the menu/driver with the bus that is required
> to attach the device?

Xen has a similar problem. They currently have tons of ugly negative
checks too. REAL_HARDWARE or similar is needed there, but it might
not fit the s390.

Checking PCI is a good start and should apply to most menus already.

I would suggest you guys come up with a common solution that works
for Xen and s390 at least (and maybe UML too?)

-Andi