Re-add support for wlr_output's atomic API

This reverts commit 724926ea6ae119956dc7b1e39c2e30c1e3657676 and
re-applies commit 6e0565e9de4247bbf0ca662565c58e0a54258d6e.

Outputs now need to be explicitly enabled when performing a modeset.
We need to roll back wlr_output_attach_render when we decide not to
render.

See also: https://github.com/swaywm/wlroots/pull/1797 (wlroots PR)
See also: https://github.com/swaywm/sway/pull/4355 (Original sway PR)
See also: https://github.com/swaywm/sway/pull/4434 (Revert sway PR)

2 files changed, 37 insertions, 30 deletions

diff --git a/sway/config/output.c b/sway/config/output.c
index 2a65718a..b8b028e6 100644
--- a/sway/config/output.c
+++ b/sway/config/output.c
@@ -231,14 +231,15 @@ struct output_config *store_output_config(struct output_config *oc) {
         return oc;
 }
 
-static bool set_mode(struct wlr_output *output, int width, int height,
+static void set_mode(struct wlr_output *output, int width, int height,
                 float refresh_rate, bool custom) {
         int mhz = (int)(refresh_rate * 1000);
 
         if (wl_list_empty(&output->modes) || custom) {
                 sway_log(SWAY_DEBUG, "Assigning custom mode to %s", output->name);
-                return wlr_output_set_custom_mode(output, width, height,
+                wlr_output_set_custom_mode(output, width, height,
                         refresh_rate > 0 ? mhz : 0);
+                return;
         }
 
         struct wlr_output_mode *mode, *best = NULL;
@@ -260,7 +261,7 @@ static bool set_mode(struct wlr_output *output, int width, int height,
         } else {
                 sway_log(SWAY_DEBUG, "Assigning configured mode to %s", output->name);
         }
-        return wlr_output_set_mode(output, best);
+        wlr_output_set_mode(output, best);
 }
 
 /* Some manufacturers hardcode the aspect-ratio of the output in the physical
@@ -315,46 +316,38 @@ bool apply_output_config(struct output_config *oc, struct sway_output *output) {
 
         if (oc && !oc->enabled) {
                 // Output is configured to be disabled
+                sway_log(SWAY_DEBUG, "Disabling output %s", oc->name);
                 if (output->enabled) {
                         output_disable(output);
                         wlr_output_layout_remove(root->output_layout, wlr_output);
                 }
                 wlr_output_enable(wlr_output, false);
-                return true;
+                return wlr_output_commit(wlr_output);
         } else if (!output->enabled) {
                 // Output is not enabled. Enable it, output_enable will call us again.
                 if (!oc || oc->dpms_state != DPMS_OFF) {
+                        sway_log(SWAY_DEBUG, "Enabling output %s", oc->name);
                         wlr_output_enable(wlr_output, true);
+                        wlr_output_commit(wlr_output);
                 }
                 return output_enable(output, oc);
         }
 
-        if (oc && oc->dpms_state == DPMS_ON) {
-                sway_log(SWAY_DEBUG, "Turning on screen");
+        if (!oc || oc->dpms_state != DPMS_OFF) {
+                sway_log(SWAY_DEBUG, "Turning on output %s", oc->name);
                 wlr_output_enable(wlr_output, true);
-        }
 
-        bool modeset_success;
-        if (oc && oc->width > 0 && oc->height > 0) {
-                sway_log(SWAY_DEBUG, "Set %s mode to %dx%d (%f Hz)", oc->name, oc->width,
-                        oc->height, oc->refresh_rate);
-                modeset_success = set_mode(wlr_output, oc->width, oc->height,
-                        oc->refresh_rate, oc->custom_mode == 1);
-        } else if (!wl_list_empty(&wlr_output->modes)) {
-                struct wlr_output_mode *mode = wlr_output_preferred_mode(wlr_output);
-                modeset_success = wlr_output_set_mode(wlr_output, mode);
-        } else {
-                // Output doesn't support modes
-                modeset_success = true;
-        }
-        if (!modeset_success) {
-                // Failed to modeset, maybe the output is missing a CRTC. Leave the
-                // output disabled for now and try again when the output gets the mode
-                // we asked for.
-                sway_log(SWAY_ERROR, "Failed to modeset output %s", wlr_output->name);
-                return false;
+                if (oc && oc->width > 0 && oc->height > 0) {
+                        sway_log(SWAY_DEBUG, "Set %s mode to %dx%d (%f Hz)", oc->name, oc->width,
+                                oc->height, oc->refresh_rate);
+                        set_mode(wlr_output, oc->width, oc->height,
+                                oc->refresh_rate, oc->custom_mode == 1);
+                } else if (!wl_list_empty(&wlr_output->modes)) {
+                        struct wlr_output_mode *mode = wlr_output_preferred_mode(wlr_output);
+                        wlr_output_set_mode(wlr_output, mode);
+                }
+                output->current_mode = wlr_output->pending.mode;
         }
-        output->current_mode = wlr_output->current_mode;
 
         float scale;
         if (oc && oc->scale > 0) {
@@ -400,6 +393,15 @@ bool apply_output_config(struct output_config *oc, struct sway_output *output) {
                 wlr_output_set_transform(wlr_output, oc->transform);
         }
 
+        sway_log(SWAY_DEBUG, "Committing output %s", wlr_output->name);
+        if (!wlr_output_commit(wlr_output)) {
+                // Failed to modeset, maybe the output is missing a CRTC. Leave the
+                // output disabled for now and try again when the output gets the mode
+                // we asked for.
+                sway_log(SWAY_ERROR, "Failed to modeset output %s", wlr_output->name);
+                return false;
+        }
+
         // Find position for it
         if (oc && (oc->x != -1 || oc->y != -1)) {
                 sway_log(SWAY_DEBUG, "Set %s position to %d, %d", oc->name, oc->x, oc->y);
@@ -417,8 +419,9 @@ bool apply_output_config(struct output_config *oc, struct sway_output *output) {
         output->height = output_box->height;
 
         if (oc && oc->dpms_state == DPMS_OFF) {
-                sway_log(SWAY_DEBUG, "Turning off screen");
+                sway_log(SWAY_DEBUG, "Turning off output %s", oc->name);
                 wlr_output_enable(wlr_output, false);
+                wlr_output_commit(wlr_output);
         }
 
         if (oc && oc->max_render_time >= 0) {
diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 6b0ceee1..b1767efc 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -560,8 +560,12 @@ int output_repaint_timer_handler(void *data) {
                 clock_gettime(CLOCK_MONOTONIC, &now);
 
                 output_render(output, &now, &damage);
-        } else if (surface_needs_frame) {
-                wlr_output_schedule_frame(output->wlr_output);
+        } else {
+                wlr_output_rollback(output->wlr_output);
+
+                if (surface_needs_frame) {
+                        wlr_output_schedule_frame(output->wlr_output);
+                }
         }
 
         pixman_region32_fini(&damage);