Looking to contributing / Roadmap?

[Drakulix]

Hey there,
as I am currently trying to develop a drm backend for smithay and I am in need of a working drm library I am looking into contributing to this library.

Do you have some kind of roadmap what still needs to be done? It currently seems to be lacking quite a bit functionality, I immediately did run into problems trying to find something like drmHandleEvent and I expect more to be missing, but this looks the most promising of all of them.

I do not have very deep knowledge about libdrm, so some hints on whats easy to do and some references would be nice.

Thanks for you work,
Drakulix

[Slabity]

Hey @Drakulix, I would definitely appreciate the help!

The end goal of this crate is to support all the features that the DRM API exposes, and act as a full replacement to mesa's libdrm. I do not have a concrete roadmap, but right now I'd like to get legacy modesetting (as in non-atomic) features working. You can use https://cgit.freedesktop.org/mesa/drm/tree/xf86drmMode.c as a guide of functions to be provided and how libdrm implements them. This is a rough state of how the crate is right now in terms of libdrm's functions:

Basic resources:

• drmModeGetResources
• drmModeGetConnector
• drmModeGetEncoder
• drmModeGetCrtc
• drmModeSetCrtc
• drmModeCrtcGetGamma
• drmModeCrtcSetGamma
• drmModeGetFB
• drmModeAddFB
• drmModeAddFB2
• drmModeAddFB2WithModifiers
• drmModeRmFB
• drmModeDirtyFB
• drmModeConnectorSetProperty (Not sure if this is necessary with below property functions)

Plane and cursor resources:

• drmModeGetPlaneResources
• drmModeGetPlane
• drmModeSetPlane
• drmModeSetCursor
• drmModeSetCursor2
• drmModeMoveCursor

Properties (mostly for atomic-modesetting):

• drmModeObjectGetProperties
• drmModeGetProperty
• drmModeObjectSetProperty
• drmModeGetPropertyBlob

Page flipping:

• drmModePageFlip
• drmModePageFlipTarget
• drmHandleEvent (usually page flipping)

Currently, legacy modesetting works (with drmModeSetCrtc), creating framebuffers from GEM buffers work, and I have also just finished dumb buffer creation and mapping. With those, you can technically get it to work as a backend for more complex rendering programs.

I also apologize for the multiple refactors. I'm still learning new (mostly undocumented) things about the DRM API that require different implementations.

I will try to explain how the library is laid out in the readme. Just give me a day or two.

[Drakulix]

Thanks! This looks like I can just start with some of the easier functions to get a hang of it, once you have written that README and then focus on the stuff, I need.

I will wait, no need to rush anything.

[Slabity]

I've added documentation to most of the control module and a readme with some very basic instructions. I'll go into more depth soon.

Ask any questions you may have.

[Drakulix]

Finally got some time. I added some questions to my first PR #4 .
Let me know what you think @Slabity :)

[Slabity]

Looks good to me. I've cleaned up my warnings and test file a bit. Hopefully the legacy_modeset test is descriptive enough to refer to.

[Slabity]

Closing in favor of tracking #25