backends/drm: always do color management on NVidia GPUs

This comes with a small performance hit but ensures that night color works

BUG: 450327
BUG: 468895

src/backends/drm/drm_egl_cursor_layer.cpp

@@ -46,7 +46,7 @@ EglGbmCursorLayer::EglGbmCursorLayer(EglGbmBackend *eglBackend, DrmPipeline *pip
 
 std::optional<OutputLayerBeginFrameInfo> EglGbmCursorLayer::beginFrame()
 {
-    return m_surface.startRendering(m_pipeline->gpu()->cursorSize(), drmToTextureRotation(m_pipeline) | TextureTransform::MirrorY, m_pipeline->cursorFormats(), m_pipeline->colorDescription(), m_pipeline->output()->channelFactors());
+    return m_surface.startRendering(m_pipeline->gpu()->cursorSize(), drmToTextureRotation(m_pipeline) | TextureTransform::MirrorY, m_pipeline->cursorFormats(), m_pipeline->colorDescription(), m_pipeline->output()->channelFactors(), m_pipeline->output()->needsColormanagement());
 }
 
 bool EglGbmCursorLayer::endFrame(const QRegion &renderedRegion, const QRegion &damagedRegion)

src/backends/drm/drm_egl_layer.cpp

@@ -59,7 +59,7 @@ std::optional<OutputLayerBeginFrameInfo> EglGbmLayer::beginFrame()
     m_scanoutBuffer.reset();
     m_dmabufFeedback.renderingSurface();
 
-    return m_surface.startRendering(m_pipeline->mode()->size(), drmToTextureRotation(m_pipeline) | TextureTransform::MirrorY, m_pipeline->formats(), m_pipeline->colorDescription(), m_pipeline->output()->channelFactors());
+    return m_surface.startRendering(m_pipeline->mode()->size(), drmToTextureRotation(m_pipeline) | TextureTransform::MirrorY, m_pipeline->formats(), m_pipeline->colorDescription(), m_pipeline->output()->channelFactors(), m_pipeline->output()->needsColormanagement());
 }
 
 bool EglGbmLayer::endFrame(const QRegion &renderedRegion, const QRegion &damagedRegion)

src/backends/drm/drm_egl_layer_surface.cpp

@@ -59,7 +59,7 @@ void EglGbmLayerSurface::destroyResources()
     m_oldSurface = {};
 }
 
-std::optional<OutputLayerBeginFrameInfo> EglGbmLayerSurface::startRendering(const QSize &bufferSize, TextureTransforms transformation, const QMap<uint32_t, QVector<uint64_t>> &formats, const ColorDescription &colorDescription, const QVector3D &channelFactors)
+std::optional<OutputLayerBeginFrameInfo> EglGbmLayerSurface::startRendering(const QSize &bufferSize, TextureTransforms transformation, const QMap<uint32_t, QVector<uint64_t>> &formats, const ColorDescription &colorDescription, const QVector3D &channelFactors, bool enableColormanagement)
 {
     if (!checkSurface(bufferSize, formats)) {
         return std::nullopt;
@@ -102,7 +102,7 @@ std::optional<OutputLayerBeginFrameInfo> EglGbmLayerSurface::startRendering(cons
             m_surface.intermediaryColorDescription = colorDescription;
         }
     }
-    if (m_surface.intermediaryColorDescription != colorDescription) {
+    if (enableColormanagement) {
         if (!m_surface.shadowBuffer) {
             m_surface.shadowTexture = std::make_shared<GLTexture>(GL_RGBA16F, m_surface.gbmSwapchain->size());
             m_surface.shadowBuffer = std::make_shared<GLFramebuffer>(m_surface.shadowTexture.get());
@@ -123,7 +123,7 @@ std::optional<OutputLayerBeginFrameInfo> EglGbmLayerSurface::startRendering(cons
 
 bool EglGbmLayerSurface::endRendering(const QRegion &damagedRegion)
 {
-    if (m_surface.intermediaryColorDescription != m_surface.targetColorDescription) {
+    if (m_surface.shadowTexture) {
         const auto &[texture, fbo] = m_surface.textureCache[m_surface.currentBuffer->bo()];
         GLFramebuffer::pushFramebuffer(fbo.get());
         ShaderBinder binder(ShaderTrait::MapTexture | ShaderTrait::TransformColorspace);

src/backends/drm/drm_egl_layer_surface.h

@@ -48,7 +48,7 @@ public:
     EglGbmLayerSurface(DrmGpu *gpu, EglGbmBackend *eglBackend, BufferTarget target = BufferTarget::Normal, FormatOption formatOption = FormatOption::PreferAlpha);
     ~EglGbmLayerSurface();
 
-    std::optional<OutputLayerBeginFrameInfo> startRendering(const QSize &bufferSize, TextureTransforms transformation, const QMap<uint32_t, QVector<uint64_t>> &formats, const ColorDescription &colorDescription, const QVector3D &channelFactors);
+    std::optional<OutputLayerBeginFrameInfo> startRendering(const QSize &bufferSize, TextureTransforms transformation, const QMap<uint32_t, QVector<uint64_t>> &formats, const ColorDescription &colorDescription, const QVector3D &channelFactors, bool enableColormanagement);
     bool endRendering(const QRegion &damagedRegion);
 
     bool doesSurfaceFit(const QSize &size, const QMap<uint32_t, QVector<uint64_t>> &formats) const;

src/backends/drm/drm_output.cpp

@@ -479,7 +479,7 @@ DrmOutputLayer *DrmOutput::cursorLayer() const
 
 bool DrmOutput::setGammaRamp(const std::shared_ptr<ColorTransformation> &transformation)
 {
-    if (!m_pipeline->active() || m_pipeline->colorimetry() != NamedColorimetry::BT709 || m_pipeline->transferFunction() != NamedTransferFunction::sRGB) {
+    if (!m_pipeline->active() || needsColormanagement()) {
         return false;
     }
     m_pipeline->setGammaRamp(transformation);
@@ -500,7 +500,7 @@ bool DrmOutput::setChannelFactors(const QVector3D &rgb)
         return true;
     }
     m_channelFactors = rgb;
-    if (m_pipeline->colorimetry() == NamedColorimetry::BT709 && m_pipeline->transferFunction() == NamedTransferFunction::sRGB) {
+    if (needsColormanagement()) {
         if (!m_pipeline->active()) {
             return false;
         }
@@ -527,4 +527,9 @@ QVector3D DrmOutput::channelFactors() const
 {
     return m_channelFactors;
 }
+
+bool DrmOutput::needsColormanagement() const
+{
+    return m_pipeline->colorimetry() != NamedColorimetry::BT709 || m_pipeline->transferFunction() != NamedTransferFunction::sRGB || m_gpu->isNVidia();
+}
 }

src/backends/drm/drm_output.h

@@ -62,6 +62,7 @@ public:
     bool setGammaRamp(const std::shared_ptr<ColorTransformation> &transformation) override;
     bool setChannelFactors(const QVector3D &rgb) override;
     QVector3D channelFactors() const;
+    bool needsColormanagement() const;
 
 private:
     bool setDrmDpmsMode(DpmsMode mode);