Subject: [PATCH V2 5/6] x86: add CONFIG_ARM_AMBA, selected by STA2X11

From: [email-masked] (Alessandro Rubini)
Date: Sun, 1 Jul 2012 12:44:01 +0200

>> The sta2x11 I/O Hub is a bridge from PCIe to AMBA. It reuses a number
>> of amba drivers and needs to activate core bus support.

> Nacked-by: H. Peter Anvin <[email-masked]>
> 
> This brings in tons of code into the x86 all{yes,mod}config builds, and 
> as perhaps one could expect some of it doesn't compile.  For example:

Ok. I apologize for not checking this. Actually, I only fixed the ones
that I needed to compile.

How should I address the problem? (original code, published on
sourceforge was simply replicating a number of amba drivers into pci
drivers, but I don't think massive code duplication is ever sensible,
thus I preferred to reuse the existing drivers).

I doubt all amba drivers can easily be made x86-compatible.
I see these possible approaces, all of them with their cons

  1- add STA2X11 dependencies to ARM_AMBA _and_ the drivers that do work

  2- leave CONFIG_ARM_AMBA undefined and play select file in Makefiles
   using obj-$(CONFIG_STA2X11)

  3- add ARM dependencies to the drivers that do not compile on x86

  any other option?

(1) and (2) bring chipset-specific stuff into the amba world, which is
bad, especially since I suspect other similar bridges will appear soon.

(3) looks like a temporary hack and stuff can be fixed over time, but
it has the disadvantage of adding a big number of needless drivers in
the dsitributions' packages -- like my nacked patch did.

thanks
/alessandro