When doing the first commit, libliftoff will try to disable all
candidate planes. This is necessary to make sure we start atomic
test commits from a clean state, and are able to incrementally come
up with a combination which works.
However, disabling a plane currently in-use on another CRTC (e.g.
a primary plane) will result in failed commits. We can't steal that
plane without removing it from the other CRTC first.
Add a new liftoff_plane.crtc_id field populated with the current
CRTC ID for the plane.
When the caller wants to perform a modeset, they will need to pass
DRM_MODE_ATOMIC_ALLOW_MODESET in the atomic commit flags, otherwise the driver
will fail the commit. libliftoff also needs to provide these flags in its
test-only commits.
On debug verbosity logging every reuse of planes is spamming the log making it
difficult to debug the process.
With this patch only the change of reusing the same allocation is logged and
how often the allocation was reused after this changed back again.
Compositors need to drive multiple connectors, each with its own vblank timings.
For each device, there's one separate rendering loop per output.
It's not possible to call liftoff_device_apply each time we want to submit a new
frame to one output, because this could touch another's output state, submitting
a new frame there in the process. When the other output will submit a new frame,
it'll get EBUSY (can't submit two frames without waiting for vblank).
Closes: https://github.com/emersion/libliftoff/issues/21
Start from scratch since we may be able to come up with a better allocation
(if the layer made another layer fall back to composition for instance).
Closes: https://github.com/emersion/libliftoff/issues/30
Keep track of the number of layer updates per 60 page-flips.
We could implement a more fine-grained tracking, for instance with a sliding
window. However it's a lot more complex than the current solution and the gains
are not clear. I'd prefer to keep the current solution and experiment with other
solutions once we have a good test-bed.
References: https://github.com/emersion/libliftoff/issues/22
