Re: [PATCH v3 0/7] Remove errors building drivers/DRIVERNAME

[Leonardo Bras]

On Mon, Oct 1, 2018 at 4:56 AM Robert Richter <rric@xxxxxxxxxx> wrote:
>
> On 27.09.18 23:08:09, Leonardo BrÃs wrote:
> > This Patchset changes some driver's Makefile to allow them building
> > using the command 'make drivers/DRIVERNAME', if compatible.
> >
> > The changed drivers would return error if the above command was run
> > on them, after an x86 allyesconfig.
>
> I don't see what you are trying to achieve here. Why shouldn't the
> command fail if it is not the intended way to call it? There are a
> couple of use cases where drivers/ is used to share common code over
> different archs and it is not always the intention to build them in
> drivers/ directly.


Sorry, I was not very clear at my reasons why this change is important,
I will try to briefly explain the whole story.

Some weeks ago I was trying to solve a task that needed to change some
compiling options, build the whole kernel (allyesconfig) and look for errors.
The problem was: It would take a long time to build everything in my computer.
And many friends with slimmer laptops would take much longer.

So, I was looking for a service that could do that for me, in the cloud.
I found out Gitlab.com offers free 50k minutes of CI for open source projects,
and allows anyone get this CI time by only forking my project, adding their
changes and pushing to Gitlab.

But Gitlab don't allow 'jobs' to take longer than 3 hours, after that the 'job'
is killed.

The kernel could not be built in 3h, not with allyesconfig. So, I created a
'job' for each directory in Linux kernel, and tried to build them separately.
All went fine, except for drivers/, which took over 3 hours.

Most logical thing was to continue the division and create five 'jobs' that
could divide the building time of drivers. To do that, each job took care of a
range of starting letters, as you can see in this link:
https://gitlab.com/LeoBras/linux-next/blob/build-ci/.gitlab-ci.yml

But then I found out some drivers were failing to build. Even if they were not
enabled in my .config. After some work I found out some drivers selection is
done in drivers/Makefile, and incompatible drivers would break my build if
tried to call them directly on drivers/DRIVERNAME.

This patchset intents to let the .config selection happen also in
drivers/DRIVERNAME/Makefile, avoiding accidentally building drivers
that are not in .config.

This would allow the kernel to be build on Gitlab CI, and would benefit many
people who wants to help in the kernel development, but have not much
processing power in their machines.

I understand my changes may have mistakes, and I am trying to fix them all.
I thank you any suggestion to make the code better.

Also, I would be happy to know of any other solution to remote build my changes
and look for warnkings / errors.


Thank you for reading,
Leonardo Bras