Re: [PATCH 2/3] x86: apuv2: fix input dependencies

From: Enrico Weigelt, metux IT consult
Date: Tue Mar 05 2019 - 08:50:48 EST

On 05.03.19 09:23, Arnd Bergmann wrote:

(CC'ing kbuild maintainer + list, hoping for better ideas :)

> No, that wouldn't be good here. In effect that means that with INPUT disabled,
> most of the x86 platform drivers are disabled, until you enable the
> PCENGINES_APU2 symbol, which then ends up showing all the other
> symbols at once, and changing them to their default states.

Okay, I didn't consider the defaults.

Maybe we should talk about step by step getting away from these defaults
(perhaps move them to the defconfigs ?) on a broader scale ... but yeah,
that's far out of scope now.

So, you've conviced me.
Add me to Reviewed-By to your patches and forget about mine.

> Another problem is that you likely run into circular dependency chains
> after trying that. The best practice for select vs. depends are

hmm, if circular deps happen, wouldn't that mean we've got some deeper
problems in here ? IMHO, dependencies should always form a DAG (except
for some really rare cases).

Do you recall any actual problem w/ input vs gpio vs. drivers ?
I'd like to have a closer look at it.

> 1. try to use 'depends on' if you can

Well, this has the unpleasant side effect that we often have to enable
a lot of things, just to even see the individual driver. For people who
just wanna configure a kernel for their board, this is a bit nasty.

But, okay, I'm going to do this w/ my own tool - I've written a small
tool that allows easy kernel reconfiguration on a higher level: you
can just pick some board templates and enable high level features like
eth, gpu, etc - it automatically creates a .config for you. I'm going
announce it on lkml soon.


Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@xxxxxxxxx -- +49-151-27565287