Message-ID: <20241202145405.58499677@foz.lan>
Date: Mon, 2 Dec 2024 14:54:05 +0100
From: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
To: Hans Verkuil <hverkuil@...all.nl>
Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org, Hans Verkuil
 <hverkuil@...ll.nl>, Ricardo Ribalda <ribalda@...omium.org>
Subject: Re: [PATCH v3 1/3] docs: media: update maintainer-entry-profile for
 multi-committers

Em Mon, 2 Dec 2024 14:17:48 +0100
Hans Verkuil <hverkuil@...all.nl> escreveu:

> Hi Mauro,
> 
> On 02/12/2024 10:26, Mauro Carvalho Chehab wrote:
> > As the media subsystem will experiment with a multi-committers model,
> > update the Maintainer's entry profile to the new rules.
> > 
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
> > Signed-off-by: Hans Verkuil <hverkuil@...ll.nl>  
> 
> xs4ll.nl -> xs4all.nl
> 
> (it's probably my typo, but please fix this in the final version)

Yes, I copied and pasted it. Will fix at the next version.

> 
> > Reviewed-by: Ricardo Ribalda <ribalda@...omium.org>
> > ---
> >  .../media/maintainer-entry-profile.rst        | 208 ++++++++++++++----
> >  MAINTAINERS                                   |   1 +
> >  2 files changed, 163 insertions(+), 46 deletions(-)
> > 
> > diff --git a/Documentation/driver-api/media/maintainer-entry-profile.rst b/Documentation/driver-api/media/maintainer-entry-profile.rst
> > index ffc712a5f632..dc764163cf1c 100644
> > --- a/Documentation/driver-api/media/maintainer-entry-profile.rst
> > +++ b/Documentation/driver-api/media/maintainer-entry-profile.rst
> > @@ -27,19 +27,139 @@ It covers, mainly, the contents of those directories:
> >  Both media userspace and Kernel APIs are documented and the documentation
> >  must be kept in sync with the API changes. It means that all patches that
> >  add new features to the subsystem must also bring changes to the
> > -corresponding API files.
> > +corresponding API documentation files.
> >  
> > -Due to the size and wide scope of the media subsystem, media's
> > -maintainership model is to have sub-maintainers that have a broad
> > -knowledge of a specific aspect of the subsystem. It is the sub-maintainers'
> > -task to review the patches, providing feedback to users if the patches are
> > +Due to the size and wide scope of the media subsystem, the media's
> > +maintainership model is to have committers that have a broad knowledge of
> > +a specific aspect of the subsystem. It is the committers' task to
> > +review the patches, providing feedback to users if the patches are
> >  following the subsystem rules and are properly using the media kernel and
> >  userspace APIs.
> >  
> > -Patches for the media subsystem must be sent to the media mailing list
> > -at linux-media@...r.kernel.org as plain text only e-mail. Emails with
> > -HTML will be automatically rejected by the mail server. It could be wise
> > -to also copy the sub-maintainer(s).
> > +Media committers
> > +----------------
> > +
> > +In the media subsystem, there are experienced developers who can push
> > +patches directly to the development tree. These developers are called
> > +Media committers and are divided into the following categories:
> > +
> > +- Committers:
> > +    contributors for one or more drivers within the media subsystem.
> > +    They can push changes to the tree that do not affect the core or ABI.
> > +
> > +- Core committers:
> > +    responsible for part of the media core. They are typically
> > +    responsible for one or more drivers within the media subsystem, but, besides
> > +    that, they can also merge patches that change the code common to multiple
> > +    drivers, including the kernel internal API.
> > +
> > +- Subsystem maintainers:
> > +    responsible for the subsystem as a whole, with access to the
> > +    entire subsystem.
> > +
> > +    Only subsystem maintainers can push changes that affect the userspace
> > +    API/ABI.
> > +
> > +All media committers shall explicitly agree with the Kernel development process
> > +as described at Documentation/process/index.rst and to the Kernel
> > +development rules inside the Kernel documentation, including its code of
> > +conduct.
> > +
> > +Media development tree
> > +----------------------
> > +
> > +The main development tree used by the media subsystem is hosted at LinuxTV.org,
> > +where we also maintain news about the subsystem, wiki pages and a patchwork
> > +instance where we track patches though their lifetime.
> > +
> > +The main tree used by media developers is at:
> > +
> > +https://git.linuxtv.org/media.git/
> > +
> > +.. _Media development workflow:
> > +
> > +Media development workflow
> > +++++++++++++++++++++++++++
> > +
> > +All changes for the media subsystem must be sent first as e-mails to the
> > +media mailing list, following the process documented at
> > +Documentation/process/index.rst.
> > +
> > +It means that patches shall be submitted as plain text only via e-mail to
> > +linux-media@...r.kernel.org. While subscription is not mandatory, you
> > +can find details about how to subscribe to it and to see its archives at:
> > +
> > +  https://subspace.kernel.org/vger.kernel.org.html
> > +
> > +Emails with HTML will be automatically rejected by the mail server.
> > +
> > +It could be wise to also copy the media committer(s). You should use
> > +``scripts/get_maintainers.pl`` to identify whom else needs to be copied.
> > +Please always copy driver's authors and maintainers.
> > +
> > +Such patches need to be based against a public branch or tag as follows:
> > +
> > +1. Patches for new features need to be based at the ``next`` branch of
> > +   media.git tree;
> > +
> > +2. Fixes against an already released kernel should preferably be against
> > +   the latest released Kernel. If they require a previously-applied
> > +   change at media.git tree, they need to be against its ``fixes`` branch.  
> 
> What is an "released kernel"? Does an -rcX kernel qualify?
> > +
> > +3. Fixes for issues not present at the latest released kernel shall
> > +   be either against a -rc kernel for an upcoming release or
> > +   against the ``fixes`` branch of the media.git tree.  
> 
> 2 and 3 remain vague, IMO. Not a blocker, but I think this needs more work
> at some point.

Some Kernel documents use "mainline release" to refer to Kernel final
releases.

One option to make it clearer would be to add a link to:
	https://www.kernel.org/category/releases.html

And then use the terms:
	- "Mainline release" for v6.10, v6.11, v6.12...
	- "Prepatch release" for -rc1, -rc2, -rc3...

What 2 and means are:

	1. Features for the next mainline release:

	   - baseline shall be media.git ``next`` branch;

	2. Fixes bugs at mainline releases:

	   - baseline shall be the latest mainline release or media.git ``fixes``  
	     if changes depend on a fix already merged;

	3. Fixes for the next mainline release:

	   - baseline shall be a prepatch release or media.git ``fixes``  
	     if changes depend on a fix already merged;

	.. Note:

	   See https://www.kernel.org/category/releases.html for an overview
	   about Kernel release types.
  
Would the above text work best you? If not please propose another
text.

In practice, we'll likely accept other baselines for fixes as
well, for practical reasons. From my side, I don't have any issues
if I need to rebase a tested bugfix patch produced against an
older Kernel send by an occasional contributor, if it only has 
trivial merge conflicts.

> > +Patches with fixes shall have:
> > +
> > +- a ``Fixes:`` tag pointing to the first commit that introduced the bug;
> > +- when applicable, a ``Cc: stable@...r.kernel.org``.
> > +
> > +Patches that were fixing bugs publicly reported by someone at the
> > +linux-media@...r.kernel.org mailing list shall have:
> > +
> > +- a ``Reported-by:`` tag immediately followed by a ``Closes:`` tag.
> > +
> > +Patches that change API shall update documentation accordingly at the
> > +same patch series.
> > +
> > +See Documentation/process/index.rst for more details about e-mail submission.
> > +
> > +Once a patch is submitted, it may follow either one of the following
> > +workflows:
> > +
> > +a. Pull request workflow: patches are handled by subsystem maintainers::
> > +
> > +     +------+   +---------+   +-------+   +-----------------------+   +---------+
> > +     |e-mail|-->|patchwork|-->|pull   |-->|maintainers merge      |-->|media.git|
> > +     +------+   |picks it |   |request|   |in media-committers.git|   +---------+
> > +                +---------+   +-------+   +-----------------------+
> > +
> > +   For this workflow, pull requests can be generated by a committer,
> > +   a previous committer, subsystem maintainers or by a trusted long-time
> > +   contributor. If you are not in such group, please don't submit
> > +   pull requests, as they will not be processed.
> > +
> > +b. Committers' workflow: patches are handled by media committers::
> > +
> > +     +------+   +---------+   +--------------------+   +-----------+   +---------+
> > +     |e-mail|-->|patchwork|-->|committers merge at |-->|maintainers|-->|media.git|
> > +     +------+   |picks it |   |media-committers.git|   |approval   |   +---------+
> > +                +---------+   +--------------------+   +-----------+
> > +
> > +On both workflows, all patches shall be properly reviewed at
> > +linux-media@...r.kernel.org before being merged at media-committers.git.
> > +
> > +When patches are picked by patchwork and when merged at media-committers,
> > +CI bots will check for errors and may provide e-mail feedback about
> > +patch problems. When this happens, the patch submitter must fix them, or
> > +explain why the errors are false positives.
> > +
> > +Patches will only be moved to the next stage in those two workflows if they
> > +don't fail on CI or if there are false-positives in the CI reports.
> > +
> > +Failures during e-mail submission
> > ++++++++++++++++++++++++++++++++++
> >  
> >  Media's workflow is heavily based on Patchwork, meaning that, once a patch
> >  is submitted, the e-mail will first be accepted by the mailing list
> > @@ -47,51 +167,48 @@ server, and, after a while, it should appear at:
> >  
> >     - https://patchwork.linuxtv.org/project/linux-media/list/
> >  
> > -If it doesn't automatically appear there after a few minutes, then
> > +If it doesn't automatically appear there after some time [2]_, then
> >  probably something went wrong on your submission. Please check if the
> > -email is in plain text\ [2]_ only and if your emailer is not mangling
> > +email is in plain text\ [3]_ only and if your emailer is not mangling
> >  whitespaces before complaining or submitting them again.
> >  
> > -You can check if the mailing list server accepted your patch, by looking at:
> > +To troubleshoot problems, you should first check if the mailing list
> > +server has accepted your patch, by looking at:
> >  
> >     - https://lore.kernel.org/linux-media/
> >  
> > -.. [2] If your email contains HTML, the mailing list server will simply
> > +If the patch is there and not at patchwork, it is likely that your e-mailer
> > +mangled the patch. Patchwork internally has a logic that checks if the  
> 
> a logic -> logic
> 
> > +received e-mail contain a valid patch. Any whitespace and new line  
> 
> contain -> contains
> 
> > +breakages mangling the patch won't be recognized by patchwork, thus such
> > +patch will be rejected.
> > +
> > +.. [2] It usually takes a few minutes for the patch to arrive, but
> > +       the e-mail server may be busy, so it may take up to a few hours
> > +       for a patch to be picked by patchwork.
> > +
> > +.. [3] If your email contains HTML, the mailing list server will simply
> >         drop it, without any further notice.
> >  
> > +.. _media-developers-gpg:
> >  
> > -Media maintainers
> > -+++++++++++++++++
> > +Authentication for pull and merge requests
> > +++++++++++++++++++++++++++++++++++++++++++
> >  
> > -At the media subsystem, we have a group of senior developers that
> > -are responsible for doing the code reviews at the drivers (also known as
> > -sub-maintainers), and another senior developer responsible for the
> > -subsystem as a whole. For core changes, whenever possible, multiple
> > -media maintainers do the review.
> > +The authenticity of developers submitting pull requests and merge requests
> > +shall be validated by using PGP sign. See: :ref:`kernel_org_trust_repository`.  
> 
> sign -> signing
> 
> Hmm, merge requests through gitlab are not signed. So this isn't correct, I
> think.

No, but they are authenticated based on gitlab's user ID. The authentication
we'll have is when the new committer sends us an e-mail providing the
gitlab's user ID.

See patch 3, as it contains some changes aiming to better explain it. Once
it get the same people reviewing that also reviewed 1 and 2, I'll fold it.

> 
> >  
> > -The media maintainers that work on specific areas of the subsystem are:
> > +With the pull request workflow, pull requests shall use a PGP-signed tag.
> >  
> > -- Remote Controllers (infrared):
> > -    Sean Young <sean@...s.org>
> > +For more details about PGP sign, please read
> > +Documentation/process/maintainer-pgp-guide.rst.
> >  
> > -- HDMI CEC:
> > -    Hans Verkuil <hverkuil@...all.nl>
> > +Subsystem maintainers
> > +---------------------
> >  
> > -- Media controller drivers:
> > -    Laurent Pinchart <laurent.pinchart@...asonboard.com>
> > -
> > -- ISP, v4l2-async, v4l2-fwnode, v4l2-flash-led-class and Sensor drivers:
> > -    Sakari Ailus <sakari.ailus@...ux.intel.com>
> > -
> > -- V4L2 drivers and core V4L2 frameworks:
> > -    Hans Verkuil <hverkuil@...all.nl>
> > -
> > -The subsystem maintainer is:
> > -  Mauro Carvalho Chehab <mchehab@...nel.org>
> > -
> > -Media maintainers may delegate a patch to other media maintainers as needed.
> > -On such case, checkpatch's ``delegate`` field indicates who's currently
> > -responsible for reviewing a patch.
> > +The subsystem maintainers are:
> > +  - Mauro Carvalho Chehab <mchehab@...nel.org> and
> > +  - Hans Verkuil <hverkuil@...all.nl>
> >  
> >  Submit Checklist Addendum
> >  -------------------------
> > @@ -108,17 +225,14 @@ implementing the media APIs:
> >  ====================	=======================================================
> >  Type			Tool
> >  ====================	=======================================================
> > -V4L2 drivers\ [3]_	``v4l2-compliance``
> > +V4L2 drivers\ [4]_	``v4l2-compliance``
> >  V4L2 virtual drivers	``contrib/test/test-media``
> >  CEC drivers		``cec-compliance``
> >  ====================	=======================================================
> >  
> > -.. [3] The ``v4l2-compliance`` also covers the media controller usage inside
> > +.. [4] The ``v4l2-compliance`` also covers the media controller usage inside  
> 
> The ``v4l2-compliance`` utility
> 
> (add 'utility')

Ok.

> 
> >         V4L2 drivers.
> >  
> > -Other compilance tools are under development to check other parts of the
> > -subsystem.
> > -
> >  Those tests need to pass before the patches go upstream.
> >  
> >  Also, please notice that we build the Kernel with::
> > @@ -134,6 +248,8 @@ Where the check script is::
> >  Be sure to not introduce new warnings on your patches without a
> >  very good reason.
> >  
> > +Please see `Media development workflow`_ for e-mail submission rules.
> > +
> >  Style Cleanup Patches
> >  +++++++++++++++++++++
> >  
> > @@ -199,7 +315,7 @@ tree between -rc6 and the next -rc1.
> >  Please notice that the media subsystem is a high traffic one, so it
> >  could take a while for us to be able to review your patches. Feel free
> >  to ping if you don't get a feedback in a couple of weeks or to ask
> > -other developers to publicly add Reviewed-by and, more importantly,
> > +other developers to publicly add ``Reviewed-by:`` and, more importantly,
> >  ``Tested-by:`` tags.
> >  
> >  Please note that we expect a detailed description for ``Tested-by:``,
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 1e930c7a58b1..c77f56a2e695 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -14510,6 +14510,7 @@ MEDIA INPUT INFRASTRUCTURE (V4L/DVB)
> >  M:	Mauro Carvalho Chehab <mchehab@...nel.org>
> >  L:	linux-media@...r.kernel.org
> >  S:	Maintained
> > +P:	Documentation/driver-api/media/maintainer-entry-profile.rst
> >  W:	https://linuxtv.org
> >  Q:	http://patchwork.kernel.org/project/linux-media/list/  
> 
> Shouldn't this point to our patchwork instance instead?

Good catch! I'll update it.

> 
> >  T:	git git://linuxtv.org/media.git  
> 
> Regards,
> 
> 	Hans



Thanks,
Mauro

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