Add CONFIG_UDMABUF to libcamera kconfigcheck

This patch adds CONFIG_UDMABUF to the libcamera kconfigcheck.

Resolves: https://gitlab.com/postmarketOS/pmaports/-/issues/3155

added 1 commit

• 683160c2 - Add CONFIG_UDMABUF to libcamera kconfigcheck

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By Alistair Francis on 2024-09-25T10:10:34

added 1 commit

• d4700b7b - Add CONFIG_UDMABUF to libcamera kconfigcheck

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By Alistair Francis on 2024-09-25T10:15:03

added 1 commit

• b0403c46 - Add CONFIG_UDMABUF to libcamera kconfigcheck

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By Alistair Francis on 2024-09-25T10:20:32

added 1 commit

• 58c54db2 - Add CONFIG_UDMABUF to libcamera kconfigcheck

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By Alistair Francis on 2024-09-25T10:24:40

Nice, thanks a lot :)

But before it becomes to easy: turns out that even if userspace doesn't use CMA heaps, the kernel might do so. On older devices for things like video decoding and zero-copy-to-display stuff, but even on more modern hardware such as sdm845 something in the kernel uses a small amount of CMA memory when available, apparently for stuff like atomic allocations

TL;DR: before removing the CMA memory again, it might make sense to check if there are non-trivial benefits from keeping it around with a small limit of 16MB or so.

P.S.: you can check the current usage with cat /proc/meminfo | grep Cma

P.S.S.: case in point https://patchwork.kernel.org/project/linux-media/cover/cover.1700544802.git.quic_vjitta@quicinc.com/

P.S.S.S.: To be clear: I don't want to unnecessary block this - please go forward and land this at any time.

By Robert Mader on 2024-09-25T22:16:25

added 18 commits

• 58c54db2...0bf40d20 - 17 commits from branch postmarketOS:master
• c429a791 - Add CONFIG_UDMABUF to libcamera kconfigcheck

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By Alistair Francis on 2024-09-25T22:06:49

changed the description

By Alistair Francis on 2024-09-25T22:06:57

resolved all threads

By Alistair Francis on 2024-09-25T22:16:25

Thanks again, LGTM!

By Robert Mader on 2024-09-25T23:08:35

approved this merge request

By Robert Eckelmann on 2024-09-26T13:49:39

approved this merge request

By Oliver Smith on 2024-09-26T17:12:48

resolved all threads

By clayton craft on 2024-09-27T19:20:24

approved this merge request

By clayton craft on 2024-09-27T19:20:29

added 12 commits

• c429a791...fcf8baf5 - 11 commits from branch postmarketOS:master
• cd3e041b - Add CONFIG_UDMABUF to libcamera kconfigcheck (MR 5628)

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By clayton craft on 2024-09-27T20:18:53

Thanks for the patch :D

By clayton craft on 2024-09-27T20:19:38

enabled an automatic merge when all merge checks for cd3e041b pass

By clayton craft on 2024-09-27T20:19:40

merged