eglfs: kms: Read page flip events on a dedicated thread

Task-number: QTBUG-74953
Change-Id: I9a630c9245d8b0afe40ade9199cf4f1d358275da
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

4 files changed, 17 insertions, 33 deletions

diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
index f4a69483bd..503419cf91 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
@@ -83,6 +83,8 @@ bool QEglFSKmsGbmDevice::open()
 
     setFd(fd);
 
+    m_eventReader.create(this);
+
     return true;
 }
 
@@ -90,6 +92,8 @@ void QEglFSKmsGbmDevice::close()
 {
     // Note: screens are gone at this stage.
 
+    m_eventReader.destroy();
+
     if (m_gbm_device) {
         gbm_device_destroy(m_gbm_device);
         m_gbm_device = nullptr;
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
index f154520669..caa1187b40 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
@@ -54,8 +54,6 @@
 
 QT_BEGIN_NAMESPACE
 
-QMutex QEglFSKmsGbmScreen::m_waitForFlipMutex;
-
 QEglFSKmsGbmIntegration::QEglFSKmsGbmIntegration()
 {
     qCDebug(qLcEglfsKmsDebug, "New DRM/KMS via GBM integration created");
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
index 333433f666..6f5c3b6953 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
@@ -110,7 +110,7 @@ QEglFSKmsGbmScreen::FrameBuffer *QEglFSKmsGbmScreen::framebufferForBufferObject(
     return fb.take();
 }
 
-QEglFSKmsGbmScreen::QEglFSKmsGbmScreen(QKmsDevice *device, const QKmsOutput &output, bool headless)
+QEglFSKmsGbmScreen::QEglFSKmsGbmScreen(QEglFSKmsDevice *device, const QKmsOutput &output, bool headless)
     : QEglFSKmsScreen(device, output, headless)
     , m_gbm_surface(nullptr)
     , m_gbm_bo_current(nullptr)
@@ -276,15 +276,12 @@ void QEglFSKmsGbmScreen::waitForFlip()
     if (!m_gbm_bo_next)
         return;
 
-    QMutexLocker lock(&m_waitForFlipMutex);
-    while (m_gbm_bo_next) {
-        drmEventContext drmEvent;
-        memset(&drmEvent, 0, sizeof(drmEvent));
-        drmEvent.version = 2;
-        drmEvent.vblank_handler = nullptr;
-        drmEvent.page_flip_handler = pageFlipHandler;
-        drmHandleEvent(device()->fd(), &drmEvent);
-    }
+    m_flipMutex.lock();
+    device()->eventReader()->startWaitFlip(this, &m_flipMutex, &m_flipCond);
+    m_flipCond.wait(&m_flipMutex);
+    m_flipMutex.unlock();
+
+    flipFinished();
 
 #if QT_CONFIG(drm_atomic)
     device()->threadLocalAtomicReset();
@@ -397,17 +394,6 @@ void QEglFSKmsGbmScreen::flip()
 #endif
 }
 
-void QEglFSKmsGbmScreen::pageFlipHandler(int fd, unsigned int sequence, unsigned int tv_sec, unsigned int tv_usec, void *user_data)
-{
-    Q_UNUSED(fd);
-    Q_UNUSED(sequence);
-    Q_UNUSED(tv_sec);
-    Q_UNUSED(tv_usec);
-
-    QEglFSKmsGbmScreen *screen = static_cast<QEglFSKmsGbmScreen *>(user_data);
-    screen->flipFinished();
-}
-
 void QEglFSKmsGbmScreen::flipFinished()
 {
     if (m_cloneSource) {
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
index b94f44b7b1..69feeee703 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
@@ -43,7 +43,8 @@
 #define QEGLFSKMSGBMSCREEN_H
 
 #include "qeglfskmsscreen.h"
-#include <QtCore/QMutex>
+#include <QMutex>
+#include <QWaitCondition>
 
 #include <gbm.h>
 
@@ -54,7 +55,7 @@ class QEglFSKmsGbmCursor;
 class QEglFSKmsGbmScreen : public QEglFSKmsScreen
 {
 public:
-    QEglFSKmsGbmScreen(QKmsDevice *device, const QKmsOutput &output, bool headless);
+    QEglFSKmsGbmScreen(QEglFSKmsDevice *device, const QKmsOutput &output, bool headless);
     ~QEglFSKmsGbmScreen();
 
     QPlatformCursor *cursor() const override;
@@ -75,18 +76,15 @@ private:
     void cloneDestFlipFinished(QEglFSKmsGbmScreen *cloneDestScreen);
     void updateFlipStatus();
 
-    static void pageFlipHandler(int fd,
-                                unsigned int sequence,
-                                unsigned int tv_sec,
-                                unsigned int tv_usec,
-                                void *user_data);
-
     gbm_surface *m_gbm_surface;
 
     gbm_bo *m_gbm_bo_current;
     gbm_bo *m_gbm_bo_next;
     bool m_flipPending;
 
+    QMutex m_flipMutex;
+    QWaitCondition m_flipCond;
+
     QScopedPointer<QEglFSKmsGbmCursor> m_cursor;
 
     struct FrameBuffer {
@@ -101,8 +99,6 @@ private:
         bool cloneFlipPending = false;
     };
     QVector<CloneDestination> m_cloneDests;
-
-    static QMutex m_waitForFlipMutex;
 };
 
 QT_END_NAMESPACE