[linux-yocto] Organization of Cfg/Features

[Darren Hart]

On 2/7/14, 13:16, "Tom Zanussi" <tom.zanussi at intel.com> wrote:

>On Fri, 2014-02-07 at 12:53 -0800, Darren Hart wrote:
>> I'm working on adding support for a specific SoC (Bay Trail
>>specifically).
>> I have a few things that it incorporates, Designware I2C, SPI,
>>I2S/Sound,
>> it needs LPSS, some PWM bits, the i915 driver, etc.
>> 
>> The i915 is separated out already, the others, not so much. I'm
>>struggling
>> with where to put them and would appreciate your thoughts.
>> 
>> I could add Designware configs to a general fragment for each of I2C and
>> SPI. Same for the UART. I looked at the sound fragment, but it says it's
>> for OSS ?!?! And doesn't include things like INTEL HDA, so it's not
>> particularly useful.
>> 
>> I considered adding a cfg/SoC directory, but that might as well be in
>>BSP
>> and I was trying to make it more reusable.
>> 
>> And that's the final option, I could create a BSP that targets just this
>> SoC and include that in the more generic intel-core* BSPs. My concern
>>with
>> this is the amount of redundancy that is likely to proliferate over
>>time.
>> 
>> The current set of cfg and features is already fairly difficult to
>> navigate.
>> 
>> And on that, my second topic.
>> 
>> As I understand it, the accepted best practice is to put cfg-only
>> fragments under cfg while things requiring patches should go under
>> features.... We've been lax if that's the case and we have a fair amount
>> of cleanup to do.
>> 
>
>If that's the case then cfg will get very crowded, since most of the
>stuff in features is cfg-only.  For that matter, since we're examining
>things afresh, why have patches in features at all - why not just put
>all the code (patches) in the machine branches?  In that case, we only
>have one location, cfg/ (or features/, whichever)...

I think this too has grown organically. However, when patches are under
heavy development, trying to maintain them in a git feature branch quickly
becomes tiresome with rebases and such.

>
>> The organization has deteriorated over time as well. I'm wondering if we
>> should have a meta-cleanup-week where we all take a block and reorg it
>>and
>> the impacted BSPs to some agreed upon standard in time for the
>> linux-yocto-dev conversion to a named release. Specifically I'm
>>wondering
>> if we should create a hierarchy in cfg that parallels the Kconfig
>> hierarchy. Drivers/net/ethernet, for example. We could cap it at 2
>>layers
>> to keep it from getting overly granular. This seems to me that it would
>> provide some direction as to how to create fragments as well as make
>>them
>> easier to find and reuse.
>> 
>> Thoughts?
>> 
>
>A cleanup would definitely be in order - I've noticed while providing
>fragments for tracing and profiling for another project that there's a
>lot of overlap and even missing bits where there should be something.
>To be expected having grown organically, but we can probably do better
>now with hindsight..
>
>Tom

Right, this wasn't a criticism but rather an observation that it's
probably time to get out the pruners and perform some deferred maintenance.

--
Darren