[libcamera-devel] [PATCH 0/2] rkisp1: don't enable immutable link

[Niklas Söderlund]

Hello,

Sorry for the very late reply, I had completely missed this thread.

On 2020-02-29 17:28:31 +0200, Laurent Pinchart wrote:
> Hi Helen,
> 
> (CC'ing Niklas)
> 
> On Wed, Feb 26, 2020 at 11:59:59PM -0300, Helen Koike wrote:
> > The following patch was merged in the Linux kernel media tree:
> > 3eed7385bff6 ("media: staging: media: rkisp1: make links immutable by default")
> > 
> > Which causes the topology configuration in libcamera to fail, since it tries to
> > enable immutable links.
> > 
> > This patchset fixes the rkisp1-capture.sh scrips and the pipeline
> > handler.
> > 
> > Question: I was wondering how releases are being mananged by libcamera.
> > Does this patchset needs to wait for the patch mentioned above to reach
> > mainline kernel?
> 
> Short answer: we don't have a release process yet :-) Longer term our
> baseline for merging code in libcamera is having corresponding support
> in mainline. For drivers not in staging, userspace API breakages are not
> allowed, so we'd need to consider that for kernel changes. For drivers
> in staging I think waiting for the change to appear in a release would
> be nice for end-users.
> 
> I think we'll need to care about backward compatibility, and handle that
> in libcamera. This may actually make it easier to change the kernel
> userspace API in a non backward-compatible way. For this specific
> change, enabling an immutable link should be a no-op, right ? We would
> then likely keep the code in libcamera, maybe with a comment explaining
> the issue, and with a scheduled removal data.
> 
> As we have no release yet, I think we can just merge the changes
> already. Niklas, any opinion ? Can you handle this ?

I think we only need to start to _really_ care about backwards 
compatibility once we have a release. So think we should merge this 
series.

I can handle this. I will test the latest media tree with this series 
and if everything works as it should I will merge it. Unfortunately I'm 
quiet swamped at the moment so will probably be at the end of the week.

> 
> > Helen Koike (2):
> >   utils: rkisp1: don't enable immutable link
> >   libcamera: pipeline: rkisp1: don't enable immutable link
> > 
> >  src/libcamera/pipeline/rkisp1/rkisp1.cpp | 8 --------
> >  utils/rkisp1/rkisp1-capture.sh           | 1 -
> >  2 files changed, 9 deletions(-)
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Regards,
Niklas Söderlund