On 2/12/2025 6:27 AM, Jacek Lawrynowicz wrote:
Hi,
Thanks for your detailed feedback and constructive suggestions. I appreciate
this as it is not easy to learn all process details otherwise.
I echo this. At times, accel feels a bit isolated from DRM.
On 2/12/2025 11:20 AM, Thomas Zimmermann wrote:
Hi,
here's a complaint about the lack of process and documentation in accel/, and
ivpu specifically. I came across this series while preparing the weekly PR for
drm-misc-next and found myself unable to extract much useful information to
report. This is a problem for a development process that relies on
transparency, accountability and collaboration. Other problematic examples are
at [1] and [2]. IIRC I had similar issues in previous development cycles.
I cannot assess the quality of the code itself, but the process and
documentation involved does not meet the requirements.
- 'Changes for <version>' is not an meaningful description for a patch series.
It's not the submitter (or anyone else) deciding that this series gets merged into
version so-and-so. The series gets merged when it is ready to be merged.
- Apparently this series contains 3 different things (buffer imports, locking,
debugging); so it should be 3 series with each addressing one of these topics.
- The series' description just restates the patch descriptions briefly. It
should rather give some indication of the problem being solved by the contained
patches, and context on why this is worth solving. (I know that this is often
complicated to state clearly to outsiders.)
We were sometimes using patchsets to bundle patches that were tested together.
We apologize for any confusion this may have caused, as we were not aware that
this approach was not preferred. Moving forward, we will ensure that patches
are split into separate series, each addressing a specific topic. I hope this
will help improve clarity and make it easier to understand and assess the
changes.
- Review should be public. I understand that it's often only one dev team
working on a specific driver, discussing issues internally. Still it makes
sense to do the code reviews in public, so that others can follow what is going
on in the driver. Public code reviews are also necessary to establish consent
and institutional knowledge within the wider developer community. You miss that
with internal reviews.
- These patches come with R-b tags pre-applied. Even for trivial changes, R-b
tags should given in public. If the R-bs have been given elsewhere, please
include a reference to that location. The tags (R-b, A-b, T-b, etc) are not
just for verifying the code itself. They also establish trust in the
development process involving each patch; and in the developers involved in
that process. This needs to happen in public to be effective.
We value all public comments and typically wait a week for public reviews
before submitting patches, regardless of whether an R-b tag is pre-applied. I
was not aware that pre-applying R-b tags was an issue. We we will ensure that
all R-b tags are added publicly from now on.
I'll provide a counter point on the pre-applied RBs - Qualcomm has been
told many times in the past decade or so to do this (GregKH comes to
mind although I'm certain he is not the only one). I don't particularly
like it, but we seem to have a reputation for poor quality in the
community, and it would appear that the first step to mitigating that is
to indicate that we have actually done internal reviews. We've been
warned that the next step is requiring a "community approved" developer
to SOB everything. I hope to avoid that.
Personally, I value community given RBs for maillist patches over
internal ones and will typically wait/seek them unless the change is
very trivial. I can't speak for The Intel/AMD/Habana folks although I
suspect they will concur with this but I lurk on IRC and of course you
have my email address. Please feel free to reach out with any feedback.
I would hope that we can learn and improve without annoying the
community to the point that the community feels frustrated and suggests
drastic action.
To Jacek, I'm hoping to be more responsive to reviewing your patches now
that we are out of the holidays and other things have settled down
again. I'm sorry if you've felt ignored.
- The kernel's (or any FOSS') development is organized around individuals, not
organizations. Having each developer send their changes individually would
likely resolve most of the current problems.
OK, I'll talk to the team about this.
I understand that accel is not graphics and can feel somewhat detached from the
rest of DRM. Yet it is part of the DRM subsystem. This development cycles' ivpu
series' made me go to IRC and ask for accel/ to be removed from the drm-misc
tree. Luckily the other maintainer were more charitable. So I make these
remarks in good faith and hope that we can improve the processes within accel/.
I appreciate your feedback and would welcome more remarks. Please keep in mind
that all accel drivers are new, and it takes time to learn all the upstream
rules.
The kernel/DRM development process is quite unique, and not everything is fully
documented. I find emails like this to be incredibly valuable and I am eager to
comply with the guidelines.
I just need some patience and guidance as I navigate through this. Thank you
for your understanding and support.
Regards,
Jacek
Best regards
Thomas
[1] https://patchwork.freedesktop.org/series/143182/
[2] https://patchwork.freedesktop.org/series/144101/
Am 04.02.25 um 09:46 schrieb Jacek Lawrynowicz:
Add possibility to import single buffer into multiple contexts,
fix locking when aborting contexts and add some debug features.
Andrzej Kacprowski (2):
accel/ivpu: Add missing locks around mmu queues
accel/ivpu: Prevent runtime suspend during context abort work
Karol Wachowski (3):
ccel/ivpu: Add debugfs interface for setting HWS priority bands
accel/ivpu: Add test modes to toggle clock relinquish disable
accel/ivpu: Implement D0i2 disable test modea
Tomasz Rusinowicz (1):
accel/ivpu: Allow to import single buffer into multiple contexts
drivers/accel/ivpu/ivpu_debugfs.c | 84 +++++++++++++++++++++++++++++++
drivers/accel/ivpu/ivpu_drv.c | 2 +-
drivers/accel/ivpu/ivpu_drv.h | 4 ++
drivers/accel/ivpu/ivpu_fw.c | 4 ++
drivers/accel/ivpu/ivpu_gem.c | 43 ++++++++++++++++
drivers/accel/ivpu/ivpu_gem.h | 1 +
drivers/accel/ivpu/ivpu_hw.c | 31 ++++++++++++
drivers/accel/ivpu/ivpu_hw.h | 5 ++
drivers/accel/ivpu/ivpu_job.c | 10 +++-
drivers/accel/ivpu/ivpu_jsm_msg.c | 29 ++++-------
drivers/accel/ivpu/ivpu_mmu.c | 9 ++++
11 files changed, 202 insertions(+), 20 deletions(-)
--
2.45.1
