1 files changed, 85 insertions, 34 deletions

diff --git a/src/platformsupport/kmsconvenience/qkmsdevice.cpp b/src/platformsupport/kmsconvenience/qkmsdevice.cpp
index 06d1251a65..7171908c99 100644
--- a/src/platformsupport/kmsconvenience/qkmsdevice.cpp
+++ b/src/platformsupport/kmsconvenience/qkmsdevice.cpp
@@ -176,6 +176,15 @@ static bool parseModeline(const QByteArray &text, drmModeModeInfoPtr mode)
     return true;
 }
 
+static inline void assignPlane(QKmsOutput *output, QKmsPlane *plane)
+{
+    if (output->eglfs_plane)
+        output->eglfs_plane->activeCrtcId = 0;
+
+    plane->activeCrtcId = output->crtc_id;
+    output->eglfs_plane = plane;
+}
+
 QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
                                                       drmModeConnectorPtr connector,
                                                       ScreenInfo *vinfo)
@@ -449,13 +458,16 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
 #endif
 
     QString planeListStr;
-    for (const QKmsPlane &plane : qAsConst(m_planes)) {
+    for (QKmsPlane &plane : m_planes) {
         if (plane.possibleCrtcs & (1 << output.crtc_index)) {
             output.available_planes.append(plane);
             planeListStr.append(QString::number(plane.id));
             planeListStr.append(QLatin1Char(' '));
-            if (plane.type == QKmsPlane::PrimaryPlane)
-                output.eglfs_plane = (QKmsPlane*)&plane;
+
+            // Choose the first primary plane that is not already assigned to
+            // another screen's associated crtc.
+            if (!output.eglfs_plane && plane.type == QKmsPlane::PrimaryPlane && !plane.activeCrtcId)
+                assignPlane(&output, &plane);
         }
     }
     qCDebug(qLcKmsDebug, "Output %s can use %d planes: %s",
@@ -477,9 +489,11 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
                     qCDebug(qLcKmsDebug, "Forcing plane index %d, plane id %u (belongs to crtc id %u)",
                             idx, plane->plane_id, plane->crtc_id);
 
-                    for (const QKmsPlane &kmsplane : qAsConst(m_planes)) {
-                        if (kmsplane.id == output.forced_plane_id)
-                            output.eglfs_plane = (QKmsPlane*)&kmsplane;
+                    for (QKmsPlane &kmsplane : m_planes) {
+                        if (kmsplane.id == output.forced_plane_id) {
+                            assignPlane(&output, &kmsplane);
+                            break;
+                        }
                     }
 
                     drmModeFreePlane(plane);
@@ -490,8 +504,37 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
         }
     }
 
-    if (output.eglfs_plane)
-        qCDebug(qLcKmsDebug, "Output eglfs plane is: %d", output.eglfs_plane->id);
+    // A more useful version: allows specifying "crtc_id,plane_id:crtc_id,plane_id:..."
+    // in order to allow overriding the plane used for a given crtc.
+    if (qEnvironmentVariableIsSet("QT_QPA_EGLFS_KMS_PLANES_FOR_CRTCS")) {
+        const QString val = qEnvironmentVariable("QT_QPA_EGLFS_KMS_PLANES_FOR_CRTCS");
+        qCDebug(qLcKmsDebug, "crtc_id:plane_id override list: %s", qPrintable(val));
+        const QStringList crtcPlanePairs = val.split(QLatin1Char(':'));
+        for (const QString &crtcPlanePair : crtcPlanePairs) {
+            const QStringList values = crtcPlanePair.split(QLatin1Char(','));
+            if (values.count() == 2 && uint(values[0].toInt()) == output.crtc_id) {
+                uint planeId = values[1].toInt();
+                for (QKmsPlane &kmsplane : m_planes) {
+                    if (kmsplane.id == planeId) {
+                        assignPlane(&output, &kmsplane);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    if (output.eglfs_plane) {
+        qCDebug(qLcKmsDebug, "Chose plane %u for output %s (crtc id %u) (may not be applicable)",
+                output.eglfs_plane->id, connectorName.constData(), output.crtc_id);
+    }
+
+#if QT_CONFIG(drm_atomic)
+    if (hasAtomicSupport() && !output.eglfs_plane) {
+        qCDebug(qLcKmsDebug, "No plane associated with output %s (crtc id %u) and atomic modesetting is enabled. This is bad.",
+                connectorName.constData(), output.crtc_id);
+    }
+#endif
 
     m_crtc_allocator |= (1 << output.crtc_index);
 
@@ -538,10 +581,6 @@ QKmsDevice::QKmsDevice(QKmsScreenConfig *screenConfig, const QString &path)
     , m_path(path)
     , m_dri_fd(-1)
     , m_has_atomic_support(false)
-#if QT_CONFIG(drm_atomic)
-    , m_atomic_request(nullptr)
-    , m_previous_request(nullptr)
-#endif
     , m_crtc_allocator(0)
 {
     if (m_path.isEmpty()) {
@@ -557,7 +596,7 @@ QKmsDevice::QKmsDevice(QKmsScreenConfig *screenConfig, const QString &path)
 QKmsDevice::~QKmsDevice()
 {
 #if QT_CONFIG(drm_atomic)
-    atomicReset();
+    threadLocalAtomicReset();
 #endif
 }
 
@@ -834,7 +873,7 @@ void QKmsDevice::discoverPlanes()
                 plane.type = QKmsPlane::Type(value);
             } else if (!strcmp(prop->name, "rotation")) {
                 plane.initialRotation = QKmsPlane::Rotations(int(value));
-                plane.availableRotations = 0;
+                plane.availableRotations = { };
                 if (propTypeIs(prop, DRM_MODE_PROP_BITMASK)) {
                     for (int i = 0; i < prop->count_enums; ++i)
                         plane.availableRotations |= QKmsPlane::Rotation(1 << prop->enums[i].value);
@@ -897,39 +936,51 @@ bool QKmsDevice::hasAtomicSupport()
 }
 
 #if QT_CONFIG(drm_atomic)
-drmModeAtomicReq * QKmsDevice::atomic_request()
+drmModeAtomicReq *QKmsDevice::threadLocalAtomicRequest()
 {
-    if (!m_atomic_request && m_has_atomic_support)
-        m_atomic_request = drmModeAtomicAlloc();
+    if (!m_has_atomic_support)
+        return nullptr;
+
+    AtomicReqs &a(m_atomicReqs.localData());
+    if (!a.request)
+        a.request = drmModeAtomicAlloc();
 
-    return m_atomic_request;
+    return a.request;
 }
 
-bool QKmsDevice::atomicCommit(void *user_data)
+bool QKmsDevice::threadLocalAtomicCommit(void *user_data)
 {
-    if (m_atomic_request) {
-        int ret = drmModeAtomicCommit(m_dri_fd, m_atomic_request,
-                          DRM_MODE_ATOMIC_NONBLOCK | DRM_MODE_PAGE_FLIP_EVENT | DRM_MODE_ATOMIC_ALLOW_MODESET, user_data);
+    if (!m_has_atomic_support)
+        return false;
 
-        if (ret) {
-           qWarning("Failed to commit atomic request (code=%d)", ret);
-           return false;
-        }
+    AtomicReqs &a(m_atomicReqs.localData());
+    if (!a.request)
+        return false;
 
-        m_previous_request = m_atomic_request;
-        m_atomic_request = nullptr;
+    int ret = drmModeAtomicCommit(m_dri_fd, a.request,
+                                  DRM_MODE_ATOMIC_NONBLOCK | DRM_MODE_PAGE_FLIP_EVENT | DRM_MODE_ATOMIC_ALLOW_MODESET,
+                                  user_data);
 
-        return true;
+    if (ret) {
+        qWarning("Failed to commit atomic request (code=%d)", ret);
+        return false;
     }
 
-    return false;
+    a.previous_request = a.request;
+    a.request = nullptr;
+
+    return true;
 }
 
-void QKmsDevice::atomicReset()
+void QKmsDevice::threadLocalAtomicReset()
 {
-    if (m_previous_request) {
-        drmModeAtomicFree(m_previous_request);
-        m_previous_request = nullptr;
+    if (!m_has_atomic_support)
+        return;
+
+    AtomicReqs &a(m_atomicReqs.localData());
+    if (a.previous_request) {
+        drmModeAtomicFree(a.previous_request);
+        a.previous_request = nullptr;
     }
 }
 #endif