mirrors/wlroots
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/wlroots/wlroots.git synced 2026-04-13 08:22:16 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Revert removal of automatic drm reset on VT switch

Browse source 
...on the basis that it reduces user-space breakage with respect to
layer-shell clients disappearing on suspend/resume and on VT change.

Revert the following two commits:

- 1edd5e2  "backend/drm: Remove reset from interface"
- 0f255b4  "backend/drm: Remove automatic reset on VT switch"

This it not intended to be reverted on the `master` branch. Instead, the
next wlroots release is anticipated to handle the situation differently,
possibly by splitting some objects and leaving output-related wl_globals
which have been announced to clients. See discussions on [issue-3944].

[issue-3944]: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3944#note_3030632

Background:

With [MR-4878] on wlroots-0.19.0, the DRM backend destroys/recreates
outputs on VT switch and in some cases on suspend/resume too. The reason
for this change was that (i) the KMS state is undefined when a VT is
switched away; and (ii) the previous outputs had issues with restoration,
particularly when the output configuration had changed whilst switched
away. This change causes two issues for users:

- Some layer-shell clients do not re-appear on output re-connection, or
  may appear on a different output. Whilst this has always been the case,
  it will now also happen in said situations. It is technically possible
  for layer-shell clients to deal with this more thoughtfully by handling
  the new-output and surface-destroy signals to achieve desired
  behaviours, but such changes take time and meanwhile Desktop Environment
  teams and other users consider this a serious regression.

- Some Gtk clients issue critical warnings on some compositors as they
  assume that at least one output is always available. This will be fixed
  in `Gtk-3.24.50` and is believed to be a harmless warning,

[MR-4878]: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4878

Testing:

1. This reversion has been tested with [conky] and [GlassyClock]. With the
reversion applied, the clients remain visible after VT switching.
2. It was also tested with labwc on tty1; and sway on tty2. No adverse
affects were observed when changing output scales on either compositor.

[conky]: https://github.com/brndnmtthws/conky
[GlassyClock]: https://github.com/tsujan/GlassyClock
This commit is contained in:
Johan Malm 2025-08-03 13:00:55 +01:00
parent 13a62a23a2
commit 175c20d954
7 changed files with 148 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

27
backend/drm/atomic.c
View file

@ -525,6 +525,33 @@ out:
return ok;
}
bool drm_atomic_reset(struct wlr_drm_backend *drm) {
struct atomic atom;
atomic_begin(&atom);
for (size_t i = 0; i < drm->num_crtcs; i++) {
struct wlr_drm_crtc *crtc = &drm->crtcs[i];
atomic_add(&atom, crtc->id, crtc->props.mode_id, 0);
atomic_add(&atom, crtc->id, crtc->props.active, 0);
}
struct wlr_drm_connector *conn;
wl_list_for_each(conn, &drm->connectors, link) {
atomic_add(&atom, conn->id, conn->props.crtc_id, 0);
}
for (size_t i = 0; i < drm->num_planes; i++) {
plane_disable(&atom, &drm->planes[i]);
}
uint32_t flags = DRM_MODE_ATOMIC_ALLOW_MODESET;
bool ok = atomic_commit(&atom, drm, NULL, NULL, flags);
atomic_finish(&atom);
return ok;
}
const struct wlr_drm_interface atomic_iface = {
.commit = atomic_device_commit,
.reset = drm_atomic_reset,
};