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Date:   Mon, 15 May 2023 10:25:25 +0100
From:   Mauro Carvalho Chehab <mchehab@kernel.org>
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Krzysztof Kozlowski <krzk@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux regressions mailing list <regressions@lists.linux.dev>,
        "Sudip Mukherjee (Codethink)" <sudipm.mukherjee@gmail.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        NXP Linux Team <linux-imx@nxp.com>,
        linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>
Subject: Re: mainline build failure due to cf21f328fcaf ("media: nxp: Add
 i.MX8 ISI driver")
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Em Mon, 15 May 2023 09:46:41 +0200
Geert Uytterhoeven <geert@linux-m68k.org> escreveu:

> Hi Krzysztof,
>=20
> On Sun, May 14, 2023 at 1:01=E2=80=AFPM Krzysztof Kozlowski <krzk@kernel.=
org> wrote:
> > On 10/05/2023 10:05, Mauro Carvalho Chehab wrote: =20
> > > And another CI job testing bisect breakages as I receive pull request=
s,
> > > applying patch per patch and using both allyesconfig and allmodconfig,
> > > also on x86_64 arch with W=3D1:
> > >
> > >       https://builder.linuxtv.org/job/patchwork/
> > >
> > > The rule is to not merge stuff on media tree if any of those jobs
> > > fail. I also fast-forward merging patches whose subject states that
> > > the build has failed.
> > >
> > > In order to help with that, on normal situation, I usually take one w=
eek
> > > to merge stuff from media_stage into media_tree, doing rebases at
> > > media_stage if needed to avoid git bisect build breakages at media_tr=
ee
> > > (which is from where I send my update PRs to you).
> > >
> > > Unfortunately, currently we don't have resources to do multiple randc=
onfig =20
> >
> > Is you media staging tree included in LKP (kernel test robot)? You would
> > get huge build coverage after every push to your staging repo. =20

No idea, as I don't know where LKP settings are stored, nor what frequency
it is doing builds from git://linuxtv.org/media_stage.git, if any. Do you k=
now
where we can check such configuration?

In the end, patches there will end going to linux-next, so at least some
sort of coverage is there, but I'm not sure if LKP will always reply to
linux-media if the patch causing build regressions is there.

While being helpful, one problem with LKP is that it is hard to filter out=
=20
reports per git tree. The only way to check if the report is applicable to
media trees seems to be looking inside the e-mail's body.

> As (multiple[*[) fixes for the build issues were submitted before the
> opening of the merge window, there must have been some build coverage,
> with even some people acting upon it...
>=20
> [*] General note, not limited to media: please apply build fixes and
>     regression fixes ASAP, to avoid multiple people running into the
>     same issues, and spending time on bisecting, investigating,
>     fixing, ...
>     Thanks a lot!

Fully agreed. That's why we opted to have a CI instance focused on media:
we should be able to program it to give feedback with the kernel build
parameters we use (Like W=3D1) and set it up in a way that it we can
customize to our needs (like testing for the architectures where media
drivers are known to be used in practice), and setting up an e-mail subject
that can be easily be filtered by our e-mail filters.

Regards,
Mauro