Automatically detect the proprietary NVidia driver and use EGLStreams accordingly

plugins/platforms/drm/drm_backend.cpp

@@ -67,11 +67,6 @@ DrmBackend::DrmBackend(QObject *parent)
     , m_udevMonitor(m_udev->monitor())
     , m_dpmsFilter()
 {
-#if HAVE_EGL_STREAMS
-    if (qEnvironmentVariableIsSet("KWIN_DRM_USE_EGL_STREAMS")) {
-        m_useEglStreams = true;
-    }
-#endif
     setSupportsGammaControl(true);
     supportsOutputChanges();
 }
@@ -482,7 +477,7 @@ DrmOutput *DrmBackend::findOutput(quint32 connector)
 bool DrmBackend::present(DrmBuffer *buffer, DrmOutput *output)
 {
     if (!buffer || buffer->bufferId() == 0) {
-        if (m_deleteBufferAfterPageFlip) {
+        if (output->gpu()->deleteBufferAfterPageFlip()) {
             delete buffer;
         }
         return false;
@@ -494,7 +489,7 @@ bool DrmBackend::present(DrmBuffer *buffer, DrmOutput *output)
             Compositor::self()->aboutToSwapBuffers();
         }
         return true;
-    } else if (m_deleteBufferAfterPageFlip) {
+    } else if (output->gpu()->deleteBufferAfterPageFlip()) {
         delete buffer;
     }
     return false;
@@ -506,9 +501,14 @@ void DrmBackend::initCursor()
 #if HAVE_EGL_STREAMS
     // Hardware cursors aren't currently supported with EGLStream backend,
     // possibly an NVIDIA driver bug
-    if (m_useEglStreams) {
-        setSoftWareCursor(true);
+    bool needsSoftwareCursor = false;
+    for (auto gpu : qAsConst(m_gpus)) {
+        if (gpu->useEglStreams()) {
+            needsSoftwareCursor = true;
+            break;
+        }
     }
+    setSoftWareCursor(needsSoftwareCursor);
 #endif
 
     m_cursorEnabled = waylandServer()->seat()->hasPointer();
@@ -604,21 +604,19 @@ Screens *DrmBackend::createScreens(QObject *parent)
 
 QPainterBackend *DrmBackend::createQPainterBackend()
 {
-    m_deleteBufferAfterPageFlip = false;
+    m_gpus.at(0)->setDeleteBufferAfterPageFlip(false);
     return new DrmQPainterBackend(this, m_gpus.at(0));
 }
 
 OpenGLBackend *DrmBackend::createOpenGLBackend()
 {
 #if HAVE_EGL_STREAMS
-    if (m_useEglStreams) {
-        m_deleteBufferAfterPageFlip = false;
+    if (m_gpus.at(0)->useEglStreams()) {
         return new EglStreamBackend(this, m_gpus.at(0));
     }
 #endif
 
 #if HAVE_GBM
-    m_deleteBufferAfterPageFlip = true;
     return new EglGbmBackend(this, m_gpus.at(0));
 #else
     return Platform::createOpenGLBackend();
@@ -642,7 +640,7 @@ QVector<CompositingType> DrmBackend::supportedCompositors() const
 #if HAVE_GBM
     return QVector<CompositingType>{OpenGLCompositing, QPainterCompositing};
 #elif HAVE_EGL_STREAMS
-    return m_useEglStreams ?
+    return m_gpus.at(0)->useEglStreams() ?
         QVector<CompositingType>{OpenGLCompositing, QPainterCompositing} :
         QVector<CompositingType>{QPainterCompositing};
 #else
@@ -661,7 +659,7 @@ QString DrmBackend::supportInformation() const
         s << "Atomic Mode Setting on GPU " << g << ": " << m_gpus.at(g)->atomicModeSetting() << Qt::endl;
     }
 #if HAVE_EGL_STREAMS
-    s << "Using EGL Streams: " << m_useEglStreams << Qt::endl;
+    s << "Using EGL Streams: " << m_gpus.at(0)->useEglStreams() << Qt::endl;
 #endif
     return supportInfo;
 }

plugins/platforms/drm/drm_backend.h

@@ -78,17 +78,6 @@ public:
     void createDpmsFilter();
     void checkOutputsAreOn();
 
-    // QPainter reuses buffers
-    bool deleteBufferAfterPageFlip() const {
-        return m_deleteBufferAfterPageFlip;
-    }
-
-#if HAVE_EGL_STREAMS
-    bool useEglStreams() const {
-        return m_useEglStreams;
-    }
-#endif
-
     QVector<CompositingType> supportedCompositors() const override;
 
     QString supportInformation() const override;
@@ -130,13 +119,9 @@ private:
     // active and enabled pipelines (above + wl_output)
     QVector<DrmOutput*> m_enabledOutputs;
 
-    bool m_deleteBufferAfterPageFlip;
     bool m_cursorEnabled = false;
     int m_pageFlipsPending = 0;
     bool m_active = false;
-#if HAVE_EGL_STREAMS
-    bool m_useEglStreams = false;
-#endif
     QVector<DrmGpu*> m_gpus;
     QScopedPointer<DpmsInputEventFilter> m_dpmsFilter;
 };

plugins/platforms/drm/drm_gpu.cpp

@@ -32,7 +32,7 @@
 namespace KWin
 {
 
-DrmGpu::DrmGpu(DrmBackend *backend, QByteArray devNode, int fd, int drmId) : m_backend(backend), m_devNode(devNode), m_fd(fd), m_drmId(drmId), m_atomicModeSetting(false), m_useEglStreams(false), m_gbmDevice(nullptr)
+DrmGpu::DrmGpu(DrmBackend *backend, QByteArray devNode, int fd, int drmId) : m_backend(backend), m_devNode(devNode), m_fd(fd), m_drmId(drmId), m_atomicModeSetting(false), m_gbmDevice(nullptr)
 {
     uint64_t capability = 0;
 
@@ -47,6 +47,12 @@ DrmGpu::DrmGpu(DrmBackend *backend, QByteArray devNode, int fd, int drmId) : m_b
     } else {
         m_cursorSize.setHeight(64);
     }
+    
+    // find out if this GPU is using the NVidia proprietary driver
+    DrmScopedPointer<drmVersion> version(drmGetVersion(fd));
+    m_useEglStreams = strstr(version->name, "nvidia-drm");
+
+    m_deleteBufferAfterPageFlip = !m_useEglStreams;
 }
 
 DrmGpu::~DrmGpu()

plugins/platforms/drm/drm_gpu.h

@@ -54,6 +54,14 @@ public:
         return m_atomicModeSetting;
     }
     
+    bool useEglStreams() const {
+        return m_useEglStreams;
+    }
+    
+    bool deleteBufferAfterPageFlip() const {
+        return m_deleteBufferAfterPageFlip;
+    }
+    
     QByteArray devNode() const {
         return m_devNode;
     }
@@ -78,6 +86,10 @@ public:
         m_eglDisplay = display;
     }
     
+    void setDeleteBufferAfterPageFlip(bool deleteBuffer) {
+        m_deleteBufferAfterPageFlip = deleteBuffer;
+    }
+    
     DrmDumbBuffer *createBuffer(const QSize &size) const {
         return new DrmDumbBuffer(m_fd, size);
     }
@@ -105,6 +117,7 @@ private:
     const int m_drmId;
     bool m_atomicModeSetting;
     bool m_useEglStreams;
+    bool m_deleteBufferAfterPageFlip;
     gbm_device* m_gbmDevice;
     EGLDisplay m_eglDisplay = EGL_NO_DISPLAY;
     

plugins/platforms/drm/drm_object_crtc.cpp

@@ -67,7 +67,7 @@ bool DrmCrtc::initProps()
 
 void DrmCrtc::flipBuffer()
 {
-    if (m_currentBuffer && m_backend->deleteBufferAfterPageFlip() && m_currentBuffer != m_nextBuffer) {
+    if (m_currentBuffer && m_gpu->deleteBufferAfterPageFlip() && m_currentBuffer != m_nextBuffer) {
         delete m_currentBuffer;
     }
     m_currentBuffer = m_nextBuffer;
@@ -98,7 +98,7 @@ bool DrmCrtc::blank()
     }
 
     if (m_output->setModeLegacy(m_blackBuffer)) {
-        if (m_currentBuffer && m_backend->deleteBufferAfterPageFlip()) {
+        if (m_currentBuffer && m_gpu->deleteBufferAfterPageFlip()) {
             delete m_currentBuffer;
             delete m_nextBuffer;
         }

plugins/platforms/drm/drm_output.cpp

@@ -65,7 +65,7 @@ void DrmOutput::teardown()
         // TODO: when having multiple planes, also clean up these
         m_primaryPlane->setOutput(nullptr);
 
-        if (m_backend->deleteBufferAfterPageFlip()) {
+        if (m_gpu->deleteBufferAfterPageFlip()) {
             delete m_primaryPlane->current();
         }
         m_primaryPlane->setCurrent(nullptr);
@@ -694,7 +694,7 @@ void DrmOutput::pageFlipped()
     }
     // Egl based surface buffers get destroyed, QPainter based dumb buffers not
     // TODO: split up DrmOutput in two for dumb and egl/gbm surface buffer compatible subclasses completely?
-    if (m_backend->deleteBufferAfterPageFlip()) {
+    if (m_gpu->deleteBufferAfterPageFlip()) {
         if (m_gpu->atomicModeSetting()) {
             if (!m_primaryPlane->next()) {
                 // on manual vt switch
@@ -784,7 +784,7 @@ bool DrmOutput::presentAtomically(DrmBuffer *buffer)
     }
 
 #if HAVE_EGL_STREAMS
-    if (m_backend->useEglStreams() && !m_modesetRequested) {
+    if (m_gpu->useEglStreams() && !m_modesetRequested) {
         // EglStreamBackend queues normal page flips through EGL,
         // modesets are still performed through DRM-KMS
         m_pageFlipPending = true;
@@ -935,7 +935,7 @@ bool DrmOutput::doAtomicCommit(AtomicCommitMode mode)
             }
 
 #if HAVE_EGL_STREAMS
-            if (!m_backend->useEglStreams())
+            if (!m_gpu->useEglStreams())
                 // EglStreamBackend uses the NV_output_drm_flip_event EGL extension
                 // to register the flip event through eglStreamConsumerAcquireAttribNV
 #endif
@@ -988,7 +988,7 @@ bool DrmOutput::atomicReqModesetPopulate(drmModeAtomicReq *req, bool enable)
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcH), mSize.height());
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcId), m_crtc->id());
     } else {
-        if (m_backend->deleteBufferAfterPageFlip()) {
+        if (m_gpu->deleteBufferAfterPageFlip()) {
             delete m_primaryPlane->current();
             delete m_primaryPlane->next();
         }

plugins/platforms/drm/drm_pointer.h

@@ -13,6 +13,7 @@
 #include <QScopedPointer>
 
 #include <xf86drmMode.h>
+#include <xf86drm.h>
 
 namespace KWin
 {
@@ -20,6 +21,15 @@ namespace KWin
 template <typename T>
 struct DrmDeleter;
 
+template <>
+struct DrmDeleter<drmVersion>
+{
+    static void cleanup(drmVersion *version)
+    {
+        drmFreeVersion(version);
+    }
+};
+
 template <>
 struct DrmDeleter<drmModeAtomicReq>
 {