Commit Graph

5 Commits

Author SHA1 Message Date
Chris Chamberlain d8ca494558 backend/drm: add wlr_drm_backend_monitor
This helper is responsible for listening for new DRM devices and
create new child DRM backends as necessary.
2021-12-13 14:55:16 +01:00
Simon Ser 0817c52a21 backend/drm: get rid of BO handle table
The BO handle table exists to avoid double-closing a BO handle,
which aren't reference-counted by the kernel. But if we can
guarantee that there is only ever a single ref for each BO handle,
then we don't need the BO handle table anymore.

This is possible if we create the handle right before the ADDFB2
IOCTL, and close the handle right after. The handles are very
short-lived and we don't need to track their lifetime.

Because of multi-planar FBs, we need to be a bit careful: some
FB planes might share the same handle. But with a small check, it's
easy to avoid double-closing the same handle (which wouldn't be a
big deal anyways).

There's one gotcha though: drmModeSetCursor2 takes a BO handle as
input. Saving the handles until drmModeSetCursor2 time would require
us to track BO handle lifetimes, so we wouldn't be able to get rid
of the BO handle table. As a workaround, use drmModeGetFB to turn the
FB ID back to a BO handle, call drmModeSetCursor2 and then immediately
close the BO handle. The overhead should be minimal since these IOCTLs
are pretty cheap.

Closes: https://github.com/swaywm/wlroots/issues/3164
2021-10-29 11:38:37 +02:00
Simon Ser 5dfaf5ea9c backend/drm: introduce wlr_drm_bo_handle_table
Using GBM to import DRM dumb buffers tends to not work well. By
using GBM we're calling some driver-specific functions in Mesa.
These functions check whether Mesa can work with the buffer.
Sometimes Mesa has requirements which differ from DRM dumb buffers
and the GBM import will fail (e.g. on amdgpu).

Instead, drop GBM and use drmPrimeFDToHandle directly. But there's
a twist: BO handles are not ref'counted by the kernel and need to
be ref'counted in user-space [1]. libdrm usually performs this
bookkeeping and is used under-the-hood by Mesa.

We can't re-use libdrm for this task without using driver-specific
APIs. So let's just re-implement the ref'counting logic in wlroots.
The wlroots implementation is inspired from amdgpu's in libdrm [2].

Closes: https://github.com/swaywm/wlroots/issues/2916

[1]: https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/110
[2]: 1a4c0ec9ae/amdgpu/handle_table.c
2021-08-25 10:05:37 -04:00
ayaka 70fb21c35b backend: make DRM and libinput backends optional
Co-authored-by: Simon Ser <contact@emersion.fr>
2021-07-22 09:56:38 -04:00
Scott Anderson cff1c2f740 meson: Various improvements
Bumps minimum version to 0.51.0

- Remove all intermediate static libraries.
  They serve no purpose and are just add a bunch of boilerplate for
  managing dependencies and options. It's now managed as a list of
  files which are compiled into libwlroots directly.

- Use install_subdir instead of installing headers individually.
  I've changed my mind since I did that. Listing them out is annoying as
  hell, and it's easy to forget to do it.

- Add not_found_message for all of our optional dependencies that have a
  meson option. It gives some hints about what option to pass and what
  the optional dependency is for.

- Move all backend subdirectories into their own meson.build. This
keeps some of the backend-specific build logic (especially rdp and
session) more neatly separated off.

- Don't overlink example clients with code they're not using.
  This was done by merging the protocol dictionaries and setting some
  variables containing the code and client header file.
  Example clients now explicitly mention what extension protocols they
  want to link to.

- Split compositor example logic from client example logic.

- Minor formatting changes
2019-12-23 07:48:29 -05:00