config: disable hw on mgpu nvidia by default (#11018)

src/config/ConfigDescriptions.hpp

@@ -1495,7 +1495,7 @@ inline static const std::vector<SConfigOptionDescription> CONFIG_OPTIONS = {
 
     SConfigOptionDescription{
         .value       = "cursor:no_hardware_cursors",
-        .description = "disables hardware cursors. Auto = disable when tearing",
+        .description = "disables hardware cursors. Auto = disable when multi-gpu on nvidia",
         .type        = CONFIG_OPTION_CHOICE,
         .data        = SConfigOptionDescription::SChoiceData{0, "Disabled,Enabled,Auto"},
     },

src/config/ConfigManager.cpp

@@ -3134,7 +3134,7 @@ bool CConfigManager::shouldUseSoftwareCursors(PHLMONITOR pMonitor) {
     switch (*PNOHW) {
         case 0: return false;
         case 1: return true;
-        case 2: return pMonitor->m_tearingState.activelyTearing;
+        case 2: return g_pHyprRenderer->isNvidia() && g_pHyprRenderer->isMgpu();
         default: break;
     }
 

src/render/Renderer.cpp

@@ -56,10 +56,12 @@ static int cursorTicker(void* data) {
 
 CHyprRenderer::CHyprRenderer() {
     if (g_pCompositor->m_aqBackend->hasSession()) {
+        size_t drmDevices = 0;
         for (auto const& dev : g_pCompositor->m_aqBackend->session->sessionDevices) {
             const auto DRMV = drmGetVersion(dev->fd);
             if (!DRMV)
                 continue;
+            drmDevices++;
             std::string name = std::string{DRMV->name, DRMV->name_len};
             std::ranges::transform(name, name.begin(), tolower);
 
@@ -71,6 +73,7 @@ CHyprRenderer::CHyprRenderer() {
 
             drmFreeVersion(DRMV);
         }
+        m_mgpu = drmDevices > 1;
     } else {
         Debug::log(LOG, "Aq backend has no session, omitting full DRM node checks");
 
@@ -2371,6 +2374,10 @@ bool CHyprRenderer::isNvidia() {
     return m_nvidia;
 }
 
+bool CHyprRenderer::isMgpu() {
+    return m_mgpu;
+}
+
 void CHyprRenderer::addWindowToRenderUnfocused(PHLWINDOW window) {
     static auto PFPS = CConfigValue<Hyprlang::INT>("misc:render_unfocused_fps");
 

src/render/Renderer.hpp

@@ -75,6 +75,7 @@ class CHyprRenderer {
     void                            onRenderbufferDestroy(CRenderbuffer* rb);
     SP<CRenderbuffer>               getCurrentRBO();
     bool                            isNvidia();
+    bool                            isMgpu();
     void                            makeEGLCurrent();
     void                            unsetEGL();
     void                            addWindowToRenderUnfocused(PHLWINDOW window);
@@ -140,6 +141,7 @@ class CHyprRenderer {
     SP<Aquamarine::IBuffer> m_currentBuffer       = nullptr;
     eRenderMode             m_renderMode          = RENDER_MODE_NORMAL;
     bool                    m_nvidia              = false;
+    bool                    m_mgpu                = false;
 
     struct {
         bool hiddenOnTouch    = false;