[Ksummit-discuss] [CORE TOPIC] Mainline kernel on a cellphone

[Krzysztof Kozlowski]

On 29.07.2015 07:09, Tim Bird wrote:
> On 07/23/2015 08:40 AM, Mark Brown wrote:
>> On Thu, Jul 23, 2015 at 08:42:51AM -0400, Steven Rostedt wrote:
>>
>>> Although is this something to be a core topic or a tech topic? Does
>>> this affect all subsystems, or just a set of drivers? Note, a core
>>> topic wont get as much time for discussion as a tech topic would.
>>
>> It's basically all subsystems that get impacted, at the minute I'd say
>> it's more a plan of action and process discussion than a technical one
>> though in the context of KS planning that's quite probably the same
>> thing.
>>
>>> Also, what is expected to be solved at KS?
>>
>> Tim Bird (Cced) has been running some sessions at other conferences
>> scoping the problem and discussing ways to move forward on this, another
>> similar session might be useful.
> 
> As Mark says, I've been working on almost exactly this topic for several
> months now.  Last year I conducted a survey investigating obstacles
> that developers (mostly corporate product developers) have in mainlining.
> There are lots of non-technical issues that are worth working on (version
> gap, corporate incentives, training, etc.), but which are outside
> the scope of the kernel summit.
> 
> There are also some technical areas where I think coordinated
> effort might be useful, to identify deficiencies and collaborate on
> progress.  These might be worth discussing at the summit.
> 
> In March of this year, I analysed code from several shipping phones
> (representing a number of different SoCs, including both ARM and
> Intel-architecture CPUs), and found that most products have between
> 1.2 and 3 million lines of code out-of-tree.  We are still in progress of
> finding patterns of out-of-treeness, to inform decisions about technical
> projects going forward.
> 
> There is now a wiki page at:
> See http://elinux.org/Kernel_areas_of_focus_for_mainlining
> In particular it has a table showing certain areas that tend to have
> a lot of out-of-tree code (e.g. most phones have between 80K to
> 100K of lines of wireless driver support out-of-mainline)

Did anyone see successful attempts of mainlining such vendor code? I
mean mainlining by individuals, not by vendor company itself.

It is a difficult task, especially without datasheets but it's possible.
At least for some drivers.

If there were such efforts, I would be curious what obstacles he/she
encountered (except a common one - missing datasheet/specs) and how he
can be helped?

Best regards,
Krzysztof