backends/drm: set removed flag on removed output modes, and use it in output configuration store

src/backends/drm/drm_output.cpp

@@ -233,10 +233,9 @@ void DrmOutput::updateConnectorProperties()
     if (!next.currentMode) {
         // some mode needs to be set
         next.currentMode = next.modes.constFirst();
-        m_pipeline->setMode(std::static_pointer_cast<DrmConnectorMode>(next.currentMode));
-        m_pipeline->applyPendingChanges();
     }
     if (!next.modes.contains(next.currentMode)) {
+        next.currentMode->setRemoved();
         next.modes.push_front(next.currentMode);
     }
 

src/core/output.cpp

@@ -62,6 +62,11 @@ OutputMode::Flags OutputMode::flags() const
     return m_flags;
 }
 
+void OutputMode::setRemoved()
+{
+    m_flags |= OutputMode::Flag::Removed;
+}
+
 OutputTransform::Kind OutputTransform::kind() const
 {
     return m_kind;

src/core/output.h

@@ -110,6 +110,7 @@ public:
     enum class Flag : uint {
         Preferred = 0x1,
         Generated = 0x2,
+        Removed = 0x4,
     };
     Q_DECLARE_FLAGS(Flags, Flag)
 
@@ -120,10 +121,12 @@ public:
     uint32_t refreshRate() const;
     Flags flags() const;
 
+    void setRemoved();
+
 private:
     const QSize m_size;
     const uint32_t m_refreshRate;
-    const Flags m_flags;
+    Flags m_flags;
 };
 
 /**

src/outputconfigurationstore.cpp

@@ -304,7 +304,7 @@ std::pair<OutputConfiguration, QList<Output *>> OutputConfigurationStore::setupT
                 && mode->refreshRate() == state.mode->refreshRate;
         });
         std::optional<std::shared_ptr<OutputMode>> mode = modeIt == modes.end() ? std::nullopt : std::optional(*modeIt);
-        if (!mode.has_value()) {
+        if (!mode.has_value() || !*mode || ((*mode)->flags() & OutputMode::Flag::Removed)) {
             mode = chooseMode(output);
         }
         *ret.changeSet(output) = OutputChangeSet{
@@ -481,7 +481,8 @@ std::shared_ptr<OutputMode> OutputConfigurationStore::chooseMode(Output *output)
     // some displays advertise bigger modes than their native resolution
     // to avoid that, take the preferred mode into account, which is usually the native one
     const auto preferred = std::find_if(modes.begin(), modes.end(), [](const auto &mode) {
-        return mode->flags() & OutputMode::Flag::Preferred;
+        return (mode->flags() & OutputMode::Flag::Preferred)
+            && !(mode->flags() & OutputMode::Flag::Removed);
     });
     if (preferred != modes.end()) {
         // some high refresh rate displays advertise a 60Hz mode as preferred for compatibility reasons