backends/drm: ignore enabled state of outputs for the lifetime of surfaces

A buffer is needed for atomic tests before the output is actually enabled

BUG: 450501
CCBUG: 450358
(cherry picked from commit e9db27d0)

src/backends/drm/egl_gbm_backend.cpp

@@ -50,8 +50,8 @@ EglGbmBackend::EglGbmBackend(DrmBackend *drmBackend, DrmGpu *gpu)
     , m_gpu(gpu)
 {
     m_gpu->setEglBackend(this);
-    connect(m_gpu, &DrmGpu::outputEnabled, this, &EglGbmBackend::addOutput);
-    connect(m_gpu, &DrmGpu::outputDisabled, this, &EglGbmBackend::removeOutput);
+    connect(m_backend, &DrmBackend::outputAdded, this, &EglGbmBackend::addOutput);
+    connect(m_backend, &DrmBackend::outputRemoved, this, &EglGbmBackend::removeOutput);
     setIsDirectRendering(true);
 }
 
@@ -207,8 +207,9 @@ bool EglGbmBackend::resetOutput(Output &output)
     return true;
 }
 
-bool EglGbmBackend::addOutput(DrmAbstractOutput *drmOutput)
+bool EglGbmBackend::addOutput(AbstractOutput *output)
 {
+    const auto drmOutput = static_cast<DrmAbstractOutput*>(output);
     Output newOutput;
     newOutput.output = drmOutput;
     if (!isPrimary() && !renderingBackend()->addOutput(drmOutput)) {
@@ -218,16 +219,16 @@ bool EglGbmBackend::addOutput(DrmAbstractOutput *drmOutput)
     return true;
 }
 
-void EglGbmBackend::removeOutput(DrmAbstractOutput *drmOutput)
+void EglGbmBackend::removeOutput(AbstractOutput *output)
 {
-    Q_ASSERT(m_outputs.contains(drmOutput));
+    Q_ASSERT(m_outputs.contains(output));
     if (isPrimary()) {
         // shadow buffer needs context current for destruction
         makeCurrent();
     } else {
-        renderingBackend()->removeOutput(drmOutput);
+        renderingBackend()->removeOutput(output);
     }
-    m_outputs.remove(drmOutput);
+    m_outputs.remove(output);
 }
 
 bool EglGbmBackend::swapBuffers(DrmAbstractOutput *drmOutput, const QRegion &dirty)

src/backends/drm/egl_gbm_backend.h

@@ -118,8 +118,8 @@ private:
 
     bool doesRenderFit(const Output &output, const Output::RenderData &render);
     bool resetOutput(Output &output);
-    bool addOutput(DrmAbstractOutput *output);
-    void removeOutput(DrmAbstractOutput *output);
+    bool addOutput(AbstractOutput *output);
+    void removeOutput(AbstractOutput *output);
 
     bool makeContextCurrent(const Output::RenderData &output) const;
     void setViewport(const Output &output) const;

[Nate Graham]

@zamundaaa apparently this caused https://bugs.kde.org/show_bug.cgi?id=450737