output: add wlr_output_state.allow_artifacts

When starting up, the compositor might call wlr_output_set_mode()
with a mode which is already the current one. wlroots will detect
this and make the wlr_output_set_mode() call a no-op. During the
next wlr_output_commit() call, wlroots will perform an atomic
commit without the ALLOW_MODESET flag.

This is an issue, because some drivers need ALLOW_MODESET even if
the mode is the same. For instance, if the FB stride or modifier
changed, some drivers require a modeset.

Add a new flag "allow_artifacts" which is set when the compositor
calls mode-setting functions. Use this flag to figure out whether
we want to perform atomic commits with ALLOW_MODESET.

(The name "allow_artifacts" is picked because ALLOW_MODESET is a
misnomer, see [1].)

[1]: https://patchwork.freedesktop.org/patch/505107/

Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3499
This commit is contained in:
Simon Ser 2022-09-28 11:09:53 +02:00 committed by Simon Zeni
parent baf3fa27dc
commit a0345f2854
3 changed files with 7 additions and 2 deletions

View file

@ -384,8 +384,7 @@ static void drm_connector_state_init(struct wlr_drm_connector_state *state,
const struct wlr_output_state *base) {
memset(state, 0, sizeof(*state));
state->base = base;
state->modeset = base->committed &
(WLR_OUTPUT_STATE_ENABLED | WLR_OUTPUT_STATE_MODE);
state->modeset = base->allow_artifacts;
state->active = (base->committed & WLR_OUTPUT_STATE_ENABLED) ?
base->enabled : conn->output.enabled;

View file

@ -79,6 +79,9 @@ enum wlr_output_state_mode_type {
*/
struct wlr_output_state {
uint32_t committed; // enum wlr_output_state_field
// Set to true to allow temporary visual artifacts (e.g. black screen) while
// the update is being applied
bool allow_artifacts;
pixman_region32_t damage; // output-buffer-local coordinates
bool enabled;
float scale;

View file

@ -4,6 +4,7 @@ void wlr_output_state_set_enabled(struct wlr_output_state *state,
bool enabled) {
state->committed |= WLR_OUTPUT_STATE_ENABLED;
state->enabled = enabled;
state->allow_artifacts = true;
}
void wlr_output_state_set_mode(struct wlr_output_state *state,
@ -11,6 +12,7 @@ void wlr_output_state_set_mode(struct wlr_output_state *state,
state->committed |= WLR_OUTPUT_STATE_MODE;
state->mode_type = WLR_OUTPUT_STATE_MODE_FIXED;
state->mode = mode;
state->allow_artifacts = true;
}
void wlr_output_state_set_custom_mode(struct wlr_output_state *state,
@ -20,6 +22,7 @@ void wlr_output_state_set_custom_mode(struct wlr_output_state *state,
state->custom_mode.width = width;
state->custom_mode.height = height;
state->custom_mode.refresh = refresh;
state->allow_artifacts = true;
}
void wlr_output_state_set_scale(struct wlr_output_state *state, float scale) {