drm: check syncobj timeline support before advertising protocol (#11117)

Prevents crashes on systems where DRM driver lacks syncobj timeline
support (e.g., Apple Silicon with Honeykrisp driver). Applications
like Zed and WezTerm would crash with 'Timeline failed importing'
when trying to use explicit sync.

Fixes #8158 #8803

---------

Co-authored-by: mvonarx <matthias.vonarx@sitrox.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/Compositor.cpp b/src/Compositor.cpp
index 53f79012..58292c8a 100644
--- a/src/Compositor.cpp
+++ b/src/Compositor.cpp
@@ -73,6 +73,7 @@
 #include <sys/resource.h>
 #include <malloc.h>
 #include <unistd.h>
+#include <xf86drm.h>
 
 using namespace Hyprutils::String;
 using namespace Aquamarine;
@@ -167,6 +168,10 @@ void CCompositor::restoreNofile() {
         Debug::log(ERR, "Failed restoring NOFILE limits");
 }
 
+bool CCompositor::supportsDrmSyncobjTimeline() const {
+    return m_bDrmSyncobjTimelineSupported;
+}
+
 void CCompositor::setMallocThreshold() {
 #ifdef M_TRIM_THRESHOLD
     // The default is 128 pages,
@@ -354,6 +359,16 @@ void CCompositor::initServer(std::string socketName, int socketFd) {
     m_drmFD = m_aqBackend->drmFD();
     Debug::log(LOG, "Running on DRMFD: {}", m_drmFD);
 
+    if (m_drmFD >= 0) {
+        uint64_t cap                   = 0;
+        int      ret                   = drmGetCap(m_drmFD, DRM_CAP_SYNCOBJ_TIMELINE, &cap);
+        m_bDrmSyncobjTimelineSupported = (ret == 0 && cap != 0);
+        Debug::log(LOG, "DRM syncobj timeline support: {}", m_bDrmSyncobjTimelineSupported ? "yes" : "no");
+    } else {
+        m_bDrmSyncobjTimelineSupported = false;
+        Debug::log(LOG, "DRM syncobj timeline support: no (no DRM FD)");
+    }
+
     if (!socketName.empty() && socketFd != -1) {
         fcntl(socketFd, F_SETFD, FD_CLOEXEC);
         const auto RETVAL = wl_display_add_socket_fd(m_wlDisplay, socketFd);