Commit graph

1050 commits

Author SHA1 Message Date
Stephane Chauveau
b790e5ea34 backend/drm: don't assume possible_crtcs has only one bit set
This isn't necessarily the case [1].

This should fix an assertion failure on Raspberry Pi 4 dual screen.

[1]: https://lists.freedesktop.org/archives/dri-devel/2020-August/275142.html

Closes: https://github.com/swaywm/wlroots/issues/1943
Co-authored-by: Simon Ser <contact@emersion.fr>
2020-12-08 18:38:42 +01:00
Simon Ser
863acb26c0 backend/drm: stop tracking overlay planes
We don't do anything with them. Once we do, we can easily add this back.
2020-12-08 18:38:42 +01:00
Simon Ser
e69bbfd0d6 backend/drm: unset current surface before importing
drm_fb_import_wlr may need to change the current EGL context. For
instance by calling drm_fb_clear, which calls wlr_buffer_unlock, which
may destroy a buffer if the cursor swapchain size has changed, which
calls gles2's destroy_buffer, which calls glDeleteFramebuffers.

Closes: https://github.com/swaywm/wlroots/issues/2479
2020-12-08 00:10:57 +01:00
Simon Ser
325cba6414
backend/drm: use EGL_PLATFORM_GBM_KHR
This is just the vendor-agnostic define for the GBM platform. It has the
same value as EGL_PLATFORM_GBM_MESA, so should work with old drivers
that only offer the Mesa-vendored extension too.
2020-12-07 12:06:38 +01:00
Simon Ser
bfb59fd4d7 backend/headless: create a config-less EGL context 2020-12-07 11:40:45 +01:00
Ilia Bozhinov
54b7ca56c0 drm: do not unset make/model before emitting destroy event 2020-12-07 10:39:29 +01:00
Simon Ser
90c8452959 backend/session/libseat: set XDG_SESSION_TYPE
libseat will call logind's SetType method if necessary.
2020-12-05 00:14:04 +01:00
Simon Ser
1336ad2a23
backend/drm: remove unused if in drm_connector_move_cursor
We return early if we don't have a plane.
2020-12-04 19:34:35 +01:00
Simon Ser
0e927533b0 backend/drm: query render formats
On some platforms it's possible that the display engine supports
modifiers not supported by the render engine.

Query render formats and intersect them with plane formats to accommodate
for this.
2020-12-03 10:52:25 +01:00
Simon Ser
237c2cf2fb backend/drm: take a wlr_drm_format in init_drm_surface
Instead of taking a format code and wlr_drm_format_set, simplify the
function signature and take a single wlr_drm_format.
2020-12-03 10:52:25 +01:00
Simon Ser
8bc5a92a98 Revert "backend/drm: stop force-probing connectors"
This reverts commit 713c1661b7.

It turns out we do need to force-probe on startup and on hotplug [1].
This is unfortunate, but that's just how the uAPI works. Fixing this
would require patching the kernel.

[1]: https://lists.freedesktop.org/archives/dri-devel/2020-November/289506.html

Closes: https://github.com/swaywm/wlroots/issues/2499
2020-12-01 11:31:03 +01:00
Simon Ser
de9ff46629
backend/drm: "scaling mode" is a connector property
It's not a CRTC property. Remove it altogether since it's unused.
2020-11-30 11:57:08 +01:00
Simon Ser
2649600fa1
backend/drm: rotation is a plane property
"rotation" is a plane property, it's not a CRTC property. It was also
missing from plane_info.
2020-11-30 11:57:08 +01:00
Simon Ser
c045253927 backend/headless: use a format suitable for rendering
When allocating buffers, use a format suitable for rendering. This
avoids picking a format that won't work.
2020-11-30 11:08:44 +01:00
Simon Ser
6485fadc16
backend/wayland: don't set EGL visual
The Wayland platform doesn't have visuals. By chance,
WL_SHM_FORMAT_ARGB8888 is zero, which means egl_get_config was ignoring
it and everything worked fine.
2020-11-25 13:52:05 +01:00
Simon Ser
713c1661b7 backend/drm: stop force-probing connectors
After discussing with Pekka and Daniel on #dri-devel, we concluded [1]
that user-space shouldn't need to force-probe connectors. Force-probing
can take some time, so using drmModeGetConnectorCurrent can result in
faster start-up.

Users can manually trigger a force-probe if necessary:

    echo detect | sudo tee /sys/class/drm/card0-DP-1/status

Or just by running a tool like drm_info.

A similar change has been submitted to Weston [2].

[1]: https://lists.freedesktop.org/archives/dri-devel/2020-November/287728.html
[2]: https://gitlab.freedesktop.org/wayland/weston/-/issues/437
2020-11-24 15:00:46 +01:00
Simon Ser
154fe8696f backend/x11: log unhandled client messages 2020-11-24 14:57:25 +01:00
Simon Ser
f6c36f8881 backend/x11: log unhandled X11 events 2020-11-24 14:57:25 +01:00
Simon Ser
52805feae9 backend/x11: log errors
Register an X11 error handler, and optionally use xcb-errors to print a
detailed message.
2020-11-24 14:57:25 +01:00
Isaac Freund
262740bc9a backend/libseat: fix change_vt return value
This should return true on success and false on failure not vice-versa.
2020-11-24 13:09:13 +01:00
Simon Ser
754179dacd backend/session: add a timeout waiting for GPUs
If a GPU doesn't show up in 10s, bail out and return zero GPUs.
2020-11-19 22:47:49 +01:00
Simon Ser
c491a21d25 backend/session/logind: log when using XDG_SESSION_ID
This makes it easier to figure out how wlroots selected the session.
2020-11-19 22:47:49 +01:00
Simon Ser
0e76f92de7 backend/session: replace session_signal with events.active
This is more idiomatic wlroots API. The new name makes it clear that the
signal is emitted when wlr_session.active changes.
2020-11-19 22:47:49 +01:00
Simon Ser
cd95d70df0 Revert "session/logind: support CanGraphical property"
We now use udev to wait for DRM card devices.

This reverts commit 3ebf079a9a.
2020-11-19 22:47:49 +01:00
Simon Ser
fbf11a41e1 backend/session: wait for DRM device if none found
Wait for a DRM device if none is found in wlr_session_find_gpus. This
can happen if the compositor is loaded before the display kernel driver.

This supersedes the logind CanGraphical property.

To test, e.g. with i915 and sway:

    rmmod -f i915
    sway &
    modprobe i915

Closes: https://github.com/swaywm/wlroots/issues/2093
2020-11-19 22:47:49 +01:00
Simon Ser
76bcddf071 backend/session: introduce wlr_session.events.add_drm_card
This is triggered when a new DRM card is added.

An easy way to test this patch is `modprobe vkms`.
2020-11-19 22:47:49 +01:00
Simon Ser
768fbaad54 backend/session: filter udev events by sysname
We're only interested in card devices. The loop over wlr_session.devices
would take care of ignoring non-card events, but a future patch will
listen to udev "add" events as well.
2020-11-19 22:47:49 +01:00
Simon Ser
44a4792fd8 backend/session: operate on wlr_device
Instead of operating on FDs in {open,close}_device, operate on
wlr_devices. This avoids the device lookup in wlr_session and allows
callers to have access to wlr_device fields.

For now, we use it to remove wlr_session_signal_add and replace it with
a more idiomatic wlr_session.events.change field. In the future, other
events will be added.
2020-11-19 22:47:49 +01:00
Simon Ser
63df2bcbe6 backend/session: don't return FD on failure in open_file
When wlr_session_open_file fails, don't return the FD, otherwise the
caller will think the call succeeded.
2020-11-19 22:47:49 +01:00
Kenny Levinsen
fb3bea8014 backend/drm: Use legacy gamma size for legacy backend
We would always return the GAMMA_LUT_SIZE property if available, and
only fall back to legacy gamma size otherwise. This leads to issues if
both are available in differs in size while we use the legacy backend.

Ensure that we only return the legacy size if we're using the legacy
backend.

Closes: https://github.com/swaywm/wlroots/issues/2429
2020-11-19 22:46:25 +01:00
Simon Ser
02df7b7ac8 backend/headless: implement export_dmabuf 2020-11-15 22:54:07 +01:00
Simon Ser
61f8cdfb9e backend/headless: switch to wlr_swapchain 2020-11-15 22:54:07 +01:00
Simon Ser
eef8b3dde8 backend/drm: check drm_surface_render_black_frame return value
This avoids hitting an assertion in drm_fb_lock_surface when
we failed to render a black frame.
2020-11-15 22:48:42 +01:00
Simon Ser
c881008e1c backend/drm: add support for wlr_swapchain multi-GPU 2020-11-15 22:48:42 +01:00
Simon Ser
8058e338ea backend/drm: get rid of wlr_drm_fb_type
Since all DRM FBs are backed by a wlr_buffer, there's no need for this
anymore.
2020-11-15 22:48:42 +01:00
Simon Ser
68a8d99055 backend/drm: add support for wlr_swapchain buffer age 2020-11-15 22:48:42 +01:00
Simon Ser
ef846a8839 backend/drm: use wlr_swapchain 2020-11-15 22:48:42 +01:00
Simon Ser
aaa3fcf66f
backend/libinput: require libinput 1.14
We have the policy of requiring up-to-date dependencies instead of
adding conditionals for older versions. libinput 1.14 was published more
than 1 year ago.
2020-11-15 18:57:16 +01:00
Mykola Orliuk
2eae9ec7c8 backend/wayland: Set cursor indivdualy per output 2020-11-12 12:31:32 +01:00
Mykola Orliuk
44531e16e0 backend/wayland: Add active pointer per host seat
Every host seat with pointer capability propagates events to one of
sub-pointer depending which output window we entered.
active_pointer tracks reference to sub-pointer on enter/leave events to
avoid lookup for it on every move events.

Fixes swaywm/wlroots#1499
2020-11-12 12:31:32 +01:00
Mykola Orliuk
ce8855ca2a backend/wayland: Bind pointer listener to seat 2020-11-12 12:31:32 +01:00
Mykola Orliuk
07e2e0f60c backend/wayland: Listen to pointers from all seats
This effectively gets swaywm/wlroots#1499 to the point where
functionality somewhat preserved and no crash happens.
We still can have only one cursor, but we can control it from multiple
seats in time-sharing manner by entering/leaving output.
2020-11-12 12:31:32 +01:00
Mykola Orliuk
44c4773d58 backend/wayland: Use seat name in input names 2020-11-12 12:31:32 +01:00
Mykola Orliuk
70ffda3ea3 backend/wayland: Add registering multiple seats 2020-11-12 12:31:32 +01:00
Mykola Orliuk
85b0872650 backend/wayland: Link input devices with seats 2020-11-12 12:31:32 +01:00
Mykola Orliuk
40bfd9f8f7 backend/wayland: Bind seat listener to wlr_wl_seat 2020-11-12 12:31:32 +01:00
Isaac Freund
e06c9e43af Remove unneeded includes from wlr_input_device.h
This uncovered many places where we were using things without directly
including them.
2020-11-11 15:40:47 +01:00
Isaac Freund
7693f61d81 Replace wlr_key_state with wl_keyboard_key_state
There's no reason to have duplicate enums
2020-11-11 10:58:38 +01:00
Simon Ser
1328477a82 backend/drm: export pending FB in export_dmabuf, if any
This allows callers to grab the current frame right after committing it,
without having to incur a full vblank worth of latency.
2020-11-05 09:43:42 +01:00
Simon Ser
ee43ef3c9d backend/drm: fix "a page-flip is already pending" errors on modeset
When performing a modeset, the DRM backend will request a page-flip
event. However frame_pending wasn't set to true, so any subsequent
wlr_output_schedule_frame calls would imemdiately trigger a synthetic
frame event, asking the compositor to submit a new frame. Committing the
new frame fails with "a page-flip is already pending" error in the DRM
backend.
2020-11-03 08:09:54 +01:00
Marten Ringwelski
85757665e6 backend/drm: Check if output is enabled before sending frame event
When an output is disabled one last pageflip will happen to disable it.
Currently this pageflip causes a frame event.
Since the output is disabled we don't want to send this frame event.
2020-10-30 10:04:54 +01:00
Mykola Orliuk
31aa7f4c95 backend/wayland: fix some keyboard/touch leaks 2020-10-18 21:25:25 +02:00
Mykola Orliuk
009cd634a2 backend/wayland: fix input creation error handling 2020-10-18 21:25:25 +02:00
Mykola Orliuk
41bf1c6871 backend/wayland: add error flow in create_wl_seat 2020-10-18 21:25:25 +02:00
Mykola Orliuk
1ac5257357 backend/wayland: factor out wlr_wl_seat 2020-10-18 16:28:12 +02:00
Mykola Orliuk
df417b7e95 backend/wayland: manage cursor for current pointer 2020-10-18 16:28:12 +02:00
Ilia Bozhinov
b98522b38f
backend/wayland: add touch support to the wayland backend
Goal currently is to get support working for a single output, thus there is only one touch device created.

Multi-output support is left for later.
2020-10-18 15:33:03 +02:00
Simon Ser
45c1a3621c backend/libinput: improve logger callback
- Add a prefix to make it clear log messages come from libinput
- Properly convert libinput log priority to wlroots'
2020-10-10 10:51:32 -04:00
Simon Ser
87836dcb55 backend: remove check for _WAYLAND_DISPLAY
I'm not sure what this was used for, but it's not used by libwayland.
Setting _WAYLAND_DISPLAY would result in the Wayland backend being
picked but would ignore the actual value of the env variable.
2020-09-16 15:53:14 -04:00
nerdopolis
e44bed0c2b Accommodate for CONFIG_VT=0, all TTYs are in seat0, but not all
seat0s have TTYs
2020-09-04 11:46:54 +02:00
Patrick Steinhardt
fa05d3cde6 session: Don't refuse unprivileged creation of "direct" backend
When starting a compositor that's using the "direct" session backend,
wlroots needs to handle calls to `drmSetMaster()` and `drmDropMaster()`.
As both calls used to require `CAP_SYS_ADMIN`, wlroots thus simply
refused starting in case the process doesn't enjoy evelated privileges.

Permission rules have changed since linux.git commit 45bc3d26c95a (drm:
rework SET_MASTER and DROP_MASTER perm handling, 2020-03-19). As a
result, starting with Linux v5.8, both ioctls will now also succeed if
the process is currently or has been the DRM master. And as the first
process to open render nodes will become the DRM master automatically,
this effectively means that process elevation is not strictly required
in all setups anymore.

So let's drop the `geteuid() != 0` permission check to allow those new
rules to do their magic.
2020-09-04 11:39:25 +02:00
Ilia Bozhinov
efe6414640 wayland: emit relative pointer events only for current pointer 2020-09-04 10:13:35 +02:00
Ryan Walklin
28cedb5623 Quieten failure to set login session type
(almost certainly due to systemd version <246)
2020-09-02 11:35:32 +02:00
Simon Ser
971de474f0 backend/session/libseat: register log handler
Route libseat errors through wlroots logging infrastructure.

This requires libseat 0.2.0.
2020-09-01 12:09:25 +02:00
Kenny Levinsen
330c50b48d session: Add missing init to direct-freebsd
bad1e9afa8 ("session: Add libseat backend") introduced a change to to
how session backends initialize, but failed to update the FreeBSD
specific version of the direct backend accordingly.

Closes: https://github.com/swaywm/wlroots/issues/2376
2020-08-26 22:56:54 +02:00
Simon Ser
297354f847 Remove unnecessary wl_display_dispatch calls
wl_display_roundtrip already takes care of dispatching the display.
2020-08-24 07:55:35 -06:00
Kenny Levinsen
bad1e9afa8 session: Add libseat backend 2020-08-24 11:13:55 +02:00
Ilia Bozhinov
9feeb2738d
backend/wayland: destroy relative pointer when output is disconnected
Fixes #2243
Fixes #2106
2020-08-17 11:33:57 +02:00
Ryan Walklin
7e990a2991 Don't set XDG_SESSION_TYPE unless logind SetType succeeds 2020-08-07 19:15:25 +02:00
Ryan Walklin
e81d2086c0 Also set XDG_SESSION_TYPE 2020-08-07 19:15:25 +02:00
Ryan Walklin
f0d03fb892 Implement logind session SetType method to change session type to wayland 2020-08-07 19:15:25 +02:00
Devin J. Pohly
aaf490d794 drm: fix uninitialized read
get_drm_prop_blob does not set path_len if it returns NULL.  Check the
return value before path_len to avoid reading uninitialized memory.

(Granted, this doesn't change the logic at all, but it does make
Valgrind a bit happier.)
2020-07-31 09:32:14 +02:00
Antonin Décimo
d9bb792794 Fix incorrect format parameters 2020-07-27 10:49:19 +02:00
Simon Ser
b6377b59ff backend/drm: check drm_surface_make_current return value
drm_connector_set_cursor wasn't checking the return value of the
drm_surface_make_current call. On failure, this results in a failed
assertion in wlr_renderer_begin (because no rendering context is
current).
2020-07-07 11:18:07 -06:00
Simon Ser
cccca368c5
backend/drm: fix typo in drm_surface_make_current arg 2020-07-07 17:36:51 +02:00
Simon Ser
f82a27f55a backend/drm: fix DPMS on legacy interface
This mirrors what the atomic code does in create_mode_blob.

Closes: https://github.com/swaywm/wlroots/issues/2312
2020-07-02 09:39:41 -06:00
Simon Ser
c930160286 backend/noop: add missing rollback_render output impl
3c5dbfd97c ("output: make rollback_render mandatory") makes a no-op
output init fail without this function.
2020-06-19 13:07:24 -06:00
Simon Ser
bf93d2e67c output: rename impl->rollback to rollback_render
The output backend API is now mostly state-less thanks to the atomic
hooks (commit and test). There is one exception though: attach_render.
This function makes the rendering context current. However sometimes the
compositor might decide not to render after attach_render (e.g. when
there's nothing new to render to the back buffer). Thus
wlr_output_rollback has been introduced to revert the pending state.

Because the output backend API is mostly state-less, the only thing
wlr_output_impl.rollback needs to do is revert the current rendering
context. Rename the function to rollback_render to make this clear. Add
a check in the common wlr_output code to only call rollback_render when
attach_buffer has been previously called.

On the long term, we'll be able to remove attach_render and
rollback_render together.
2020-06-19 11:50:42 -06:00
Andri Yngvason
a6a5a19356 backend: drm: Fix dmabuf resource leak 2020-06-13 15:39:49 +02:00
Simon Ser
e77c046cf9 backend/drm: fix stack overflow in dealloc_crtc
Call drm_crtc_commit directly instead of calling drm_connector_set_mode.
This restores the previous behaviour where conn_enable was called [1].

[1]: 0c7c562482/backend/drm/drm.c (L1093)

Closes: https://github.com/swaywm/wlroots/issues/2253
2020-06-08 10:13:00 -06:00
Tudor Brindus
dc13bb827d util: fix and move get_current_time_msec into a util file
This commit makes `get_current_time_msec` correctly return milliseconds
as opposed to microseconds. It also considers the value of `tv_sec`, so
we don't lose occasionally go back in time by one second. Finally, the
function is moved into `util/time.cc` so that it can be reused elsewhere
without having to consider these pitfalls.
2020-06-06 00:09:19 +02:00
Simon Ser
8f28f5b2f8 backend/drm: fix black screens when enabling output
This patch fixes this failure:

    01:57:16.642 [ERROR] [backend/drm/drm.c:360] Failed to page-flip output 'eDP-1': a page-flip is already pending
    01:57:16.684 [ERROR] [backend/drm/drm.c:360] Failed to page-flip output 'eDP-1': a page-flip is already pending
    01:57:16.684 [ERROR] [backend/drm/drm.c:732] Failed to initialize renderer on connector 'eDP-1': initial page-flip failed
    01:57:16.684 [ERROR] [backend/drm/drm.c:805] Failed to initialize renderer for plane
    01:57:16.684 [sway/config/output.c:423] Failed to commit output eDP-1

References: https://github.com/swaywm/sway/issues/5101
2020-06-03 10:27:21 -06:00
Simon Ser
019fe8bb7e backend/wayland: fix spurious eglSwapBuffers failures
This was introduced in [1]. However after reverting that PR I still
can't reproduce the bug the PR aimed to fix [2].

Since there's no good explanation why we would need to swap buffers
before resizing, let's just revert the PR.

[1]: https://github.com/swaywm/wlroots/pull/1486
[2]: https://github.com/swaywm/wlroots/issues/1371

Closes: https://github.com/swaywm/wlroots/issues/1768
2020-06-02 14:14:08 -06:00
Tudor Brindus
47a30957d1 backend/wayland: scale tablet tool position into [0, 1] range
Fixes #2233.
2020-06-01 22:36:46 +02:00
Simon Ser
b03eebf7d4 backend/drm: always perform a CRTC commit in drm_connector_commit
When the mode, status or buffer hasn't changed, drm_connector_commit was
a no-op. Because of this individual changes to the gamma LUT or adaptive
sync status were ignored (if committed without a buffer).

Instead, perform a commit to apply the changes.
2020-06-01 11:45:11 -06:00
Simon Ser
1a2e82e327 backend/drm: drop extra wlr_output_update_enabled call
drm_connector_set_mode already takes care of keeping this up-to-date.
2020-06-01 11:45:11 -06:00
Simon Ser
80467f6ae8 backend/drm: commit/rollback FBs in drm_crtc_commit
We need to perform the FB bookkeeping on all commits, not just on
page-flips.
2020-06-01 11:45:11 -06:00
Simon Ser
70f3a0bb27 backend/drm: make adaptive_sync atomic
Stop using drmModeObjectSetProperty, set the property in the crtc_commit
function instead.
2020-06-01 11:45:11 -06:00
Simon Ser
42126c2022 backend/drm: rollback pending CRTC state on test commit
A test commit doesn't apply the pending state.

The CRTC state will be populated again if the compositor decides to
perform a regular commit afterwards.
2020-06-01 11:45:11 -06:00
Simon Ser
1a23c1425f Add comments for missing tablet tool entries
And stop using default cases, so that we know which parts of the code
need an update when adding a new enum entry.

Closes: https://github.com/swaywm/wlroots/issues/2208
2020-05-28 15:13:05 +02:00
Simon Ser
d66b9966e9 backend/drm: fix missing crtc->cursor NULL check
Fixes: cdb6fdbc6c ("backend/drm: remove missing cursor plane workaround")
2020-05-27 21:01:20 +02:00
Simon Ser
e7a8ea84c3 backend/drm: don't set cursor if off-screen
Closes: https://github.com/swaywm/wlroots/issues/2216
2020-05-27 21:01:20 +02:00
Simon Ser
15d8f1806e backend/drm: introduce pending and current CRTC state
Previously, we only had the pending state (crtc->pending, crtc->mode and
crtc->active). This causes issues when a commit fails: the pending state
is left as-is, and the next commit may read stale data from it.

This will also cause issues when implementing test-only commits: we need
to rollback the pending CRTC state after a test-only commit.

Introduce separate pending and current CRTC states. Properly update the
current state after a commit.
2020-05-26 23:34:37 +02:00
Simon Ser
d6cc718472 backend/drm: nuke retry_pageflip
retry_pageflip is now dead code, since drm_connector_start_renderer
isn't called anymore. It was previously called when enabling an output.
The name "retry_pageflip" was a little confusing because the function
retried a modeset and the timer wasn't set up while performing a simple
page-flip.

Let's just remove this altogether for now. We can discuss whether it's
worth it to bring it back. Should we only do it on failed page-flips?
Should we only do it on EBUSY?
2020-05-26 23:34:37 +02:00
Simon Ser
61095f4a12 backend/drm: make drm_connector_set_mode take a wlr_drm_connector
Since this is an internal DRM backend function, there's no reason we
need to take a generic wlr_output.
2020-05-26 23:34:37 +02:00
Simon Ser
445750aa9a backend/drm: remove enable_drm_connector
Merge enable_drm_connector into drm_connector_set_mode. This allows us
to de-duplicate logic since enabling an output performs a modeset.
2020-05-26 23:34:37 +02:00
Simon Ser
c02e9c2bb1 backend/drm: remove drm_connector_set_custom_mode
Replace it with a function that returns the pending mode.
2020-05-26 23:34:37 +02:00
Simon Ser
21c6cc5e4c backend/drm: refuse to enable an output without a mode 2020-05-26 20:10:55 +02:00
Simon Ser
47e5212823 backend/drm: rollback atomic blobs
If the atomic commit fails or is test-only, rollback
wlr_drm_crtc.{mode_id,gamma_lut} blob IDs to their previous value. This
prevents the next commits from failing or applying test-only state.
2020-05-26 20:01:38 +02:00
Simon Ser
af2f69e6c1 render/egl: unset current context after swapping buffers
After swapping buffers, it doesn't make sense to perform more rendering
operations. Unset the context to reflect this.

This commit makes it so the context is always only current between
wlr_egl_make_current and wlr_egl_swap_buffers.

This is an alternative to [1].

[1]: https://github.com/swaywm/wlroots/pull/2212
2020-05-20 17:39:34 +02:00