This moves the magic incantation into libdrm and is clearer. See
[1] for details.
While at it, fixup the doc comment and improve logging.
[1]: 523b3658aa
libseat provides all session functionality, so there is no longer need
for a session backend abstraction. The libseat device ID, seat handle
and event loop handle are moved to the main wlr_session and wlr_device
structs.
Sometimes wlr_session_find_gpus will encounter an error. This is
different from finding zero GPUs.
On error, wlr_session_find_gpus already returns -1. However, this is
casted to size_t, so callers uncorrectly assume this is a success.
Instead, make wlr_session_find_gpus return a ssize_t and allow callers
to handle the error accordingly.
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
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.
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.
The documentation for wayland-server.h says:
> Use of this header file is discouraged. Prefer including
> wayland-server-core.h instead, which does not include the server protocol
> header and as such only defines the library PI, excluding the deprecated API
> below.
Replacing wayland-server.h with wayland-server-core.h allows us to drop the
WL_HIDE_DEPRECATED declaration.
This is the first step towards being able to run via DRM leasing and on render
nodes.
Test with:
export WLR_BACKENDS=drm
export WLR_SESSION=noop
export WLR_DRM_DEVICES=/dev/dri/renderD128
On some systems (most notably laptops with two GPUs) there are GPUs that
don't have attached outputs. However, we still want to load those GPUs
because they could still be used by the compositor for rendering.
