Re: Hardware dependencies in Kconfig

[Michal Marek <mmarek@suse.cz>]

On 2014-04-15 06:52, Greg KH wrote:
> On Mon, Apr 14, 2014 at 11:12:54PM +0200, Jean Delvare wrote:
>> I'm very fine with USB drivers being architecture-agnostic. They really
>> are. But in practice a lot of PCI and platform drivers are only useful
>> of one architecture, of a few ones at best.
> 
> Why would PCI devices only be useful on one architecture?  PCI works on
> almost all arches that Linux supports, if it's a PCI card, it could be
> on any of those processors.  If it's a mini-pci, the chances are less,
> but still quite possible.

"PCI device" does not necessarily imply any of the PCI/PCIe form
factors. Looking at my desktop machine, neither the integrated graphics
core nor the Intel Management Engine thing are cards that I could plug
into an ARM router with a PCI slot. So the i915 and mei drivers are
properly annotated with 'depends on X86' and one is not bothered with
the prompts when building a kernel for an ARM router.


> Yes, it's a pain for distros, and yes, it would be nice if people wrote
> better Kconfig help text.  Pushing back on that is the key here.  If you
> see new drivers show up that you don't know where they work on, ask the
> developers and make up patches.

Better help texts would be nice, but what would really help is some
machine-readable annotation. 'depends on <arch/mach> || COMPILE_TEST' is
already available, so why not use it.

Michal