x11: never enable DPMS if we didn't disable it

Enabling DPMS even though you disabled it globally is pretty unfriendly,
so don't do it. Instead, we only disable DPMS if it was enabled, and
only enable it if we disabled it ourselves.

The other way should never happen (disabling DPMS permanently), unless
mpv crashes during playback.

2 files changed, 4 insertions, 0 deletions

diff --git a/video/out/x11_common.c b/video/out/x11_common.c
index 89cded6b5d..911fea3ddc 100644
--- a/video/out/x11_common.c
+++ b/video/out/x11_common.c
@@ -1562,12 +1562,15 @@ static void set_screensaver(struct vo_x11_state *x11, bool enabled)
         BOOL onoff = 0;
         CARD16 state;
         DPMSInfo(mDisplay, &state, &onoff);
+        if (!x11->dpms_touched && enabled)
+            return; // enable DPMS only we we disabled it before
         if (enabled != !!onoff) {
             MP_VERBOSE(x11, "Setting DMPS: %s.\n", enabled ? "on" : "off");
             if (enabled) {
                 DPMSEnable(mDisplay);
             } else {
                 DPMSDisable(mDisplay);
+                x11->dpms_touched = true;
             }
             DPMSInfo(mDisplay, &state, &onoff);
             if (enabled != !!onoff)
diff --git a/video/out/x11_common.h b/video/out/x11_common.h
index 0b4a58325f..15a86978ec 100644
--- a/video/out/x11_common.h
+++ b/video/out/x11_common.h
@@ -41,6 +41,7 @@ struct vo_x11_state {
     struct mp_rect screenrc;
 
     bool screensaver_enabled;
+    bool dpms_touched;
     double screensaver_time_last;
 
     XIM xim;