Select system Vulkan on Mali devices

app/src/main/cpp/waylandcomp/src/vk_loader.c

@@ -32,7 +32,7 @@ int vk_loader_open(const char *driver_path, const char *library_name,
         g_handle = dlopen("libvulkan.so", RTLD_LOCAL | RTLD_NOW);
         __android_log_print(ANDROID_LOG_WARN, TAG,
                             "no adrenotools driver -> system libvulkan handle=%p "
-                            "(dmabuf import likely unsupported)", g_handle);
+                            "(dma-buf import depends on system driver)", g_handle);
     }
     if (!g_handle) return -1;
     g_gip = (PFN_vkGetInstanceProcAddr)dlsym(g_handle, "vkGetInstanceProcAddr");

app/src/main/java/com/droiddeck/launcher/MainActivity.kt

@@ -433,7 +433,7 @@ class MainActivity : ComponentActivity() {
                 showNonAdreno?.let { release ->
                     ConfirmDialog(
                         title = "Not an Adreno GPU",
-                        text = "Turnip supports Adreno GPUs. On ${com.droiddeck.launcher.core.DeviceSupport.gpuName()}, Steam may show a black screen. Download: ${"%.0f".format(release.size / 1e6)} MB.",
+                        text = "The Linux runtime's bundled Vulkan driver targets Adreno GPUs. On ${com.droiddeck.launcher.core.DeviceSupport.gpuName()}, Steam may show a black screen. Download: ${"%.0f".format(release.size / 1e6)} MB.",
                         confirm = "Install anyway",
                         onConfirm = { showNonAdreno = null; install(release) },
                         onDismiss = { showNonAdreno = null },
@@ -1113,14 +1113,14 @@ class MainActivity : ComponentActivity() {
             Thread({ checkCatalog() }, "catalog").start()
             return
         }
-        // The runtime draws with Turnip, an Adreno driver: on Mali, Xclipse or PowerVR the
-        // compositor gets no usable Vulkan device and a session is sound over a black screen.
-        // Said before the download, not after it; the user may still go ahead.
+        // The bundled Linux runtime Vulkan ICD is Freedreno, which targets Adreno. The Android
+        // compositor can use a non-Adreno system driver, but Steam may still have no guest Vulkan
+        // device. Warn before the download; the user may still go ahead.
         if (installed == null && !com.droiddeck.launcher.core.DeviceSupport.adreno()) { showNonAdreno = release; return }
         install(release)
     }
 
-    /** Starts a session; with no runtime on a non-Adreno, the same warning Setup gives comes first, before any download. */
+    /** Starts a session; with no runtime on a non-Adreno, show the guest Vulkan warning before download. */
     private fun startSession(intent: Intent, steamSession: Boolean = false) {
         refreshPhantomStatus()
         if (steamSession && PhantomProcessLimit.blocksSteam(phantomProcessStatus)) {

app/src/main/java/com/droiddeck/launcher/core/DeviceSupport.kt

@@ -4,13 +4,12 @@ import android.os.Build
 import java.io.File
 
 /**
- * Whether this device can draw a Linux session at all.
+ * Whether the bundled Linux runtime's Vulkan renderer is likely to work.
  *
- * The runtime draws with Turnip, an Adreno driver. On Mali, Xclipse and PowerVR the compositor
- * gets no usable Vulkan device and a session comes up as sound over a black screen - a failure
- * with nothing in it to read. The app cannot fix that, so it says so before the download rather
- * than after it. Adreno is recognised by what only Qualcomm's stack has: the KGSL node, or the
- * vendor's own Vulkan driver at its usual path.
+ * The runtime currently ships the Freedreno Vulkan ICD, which targets Adreno. The Android
+ * compositor uses a separate driver and can use a non-Adreno system Vulkan implementation. This
+ * check gates the guest-driver warning. Adreno is recognised by what only Qualcomm's stack has:
+ * the KGSL node, or the vendor's own Vulkan driver at its usual path.
  */
 object DeviceSupport {
     fun adreno(): Boolean =

app/src/main/java/com/droiddeck/launcher/gpu/TurnipDriver.java

@@ -5,6 +5,7 @@ import android.net.Uri;
 import android.os.Environment;
 import android.util.Log;
 
+import com.droiddeck.launcher.core.DeviceSupport;
 import com.droiddeck.launcher.core.FileUtils;
 import com.droiddeck.launcher.core.TarZst;
 import com.droiddeck.launcher.session.SessionPrefs;
@@ -24,11 +25,11 @@ import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
 /**
- * The Vulkan driver the in-app compositor runs on. It has to be Turnip: the system Adreno driver
- * does not implement VK_EXT_image_drm_format_modifier, so importing the dma-bufs gamescope hands
- * over fails and the session renders nothing. Two builds ship in the apk, one per Adreno
- * generation, and the GPU decides which is unpacked - unless the user has imported an AdrenoTools
- * zip of their own and chosen it, which then wins.
+ * The Vulkan driver the in-app compositor runs on. On Adreno it needs Turnip: the system Adreno
+ * driver does not implement VK_EXT_image_drm_format_modifier, so importing the dma-bufs gamescope
+ * hands over fails and the session renders nothing. The bundled builds are Adreno-only; on other
+ * GPUs, use the system driver. The GPU decides which Turnip build is unpacked - unless the user
+ * has imported an AdrenoTools zip of their own and chosen it, which then wins.
  *
  * <p>The guest's own Turnip is a different copy entirely - a glibc build inside the rootfs, or an
  * imported one ({@link LinuxVulkanDriverManager}). This one is the bionic build the app process
@@ -39,8 +40,8 @@ import java.util.zip.ZipInputStream;
  * {@code meta.json} whose {@code libraryName} names the .so beside it - the AdrenoTools layout.
  * The import path is ported from Bannerlator's {@code AdrenotoolsManager} (GPL-3.0), including
  * the refusal of zips that belong in the Linux runtime list: a "-Linux" (glibc) Turnip names no
- * library on purpose, and installed here it would put the compositor on the system Vulkan - a
- * black screen wearing a driver's name.
+ * library on purpose, and installed here it would put the compositor on the system Vulkan while
+ * appearing to select a driver.
  */
 public final class TurnipDriver {
     private static final String TAG = "TurnipDriver";
@@ -267,8 +268,7 @@ public final class TurnipDriver {
 
     /**
      * Unpacks the driver this device needs and returns its id, or null to fall back to the system
-     * Vulkan loader (which means a black session on Adreno, but is better than refusing to start
-     * on a GPU neither build covers).
+     * Vulkan loader. The system driver must provide the compositor's Vulkan and dma-buf extensions.
      */
     public String install() {
         String id = choose();
@@ -322,6 +322,10 @@ public final class TurnipDriver {
             if (forced.startsWith("a8")) return DRIVER_A8XX;
             if (forced.startsWith("a7")) return DRIVER_A7XX;
         }
+        if (!DeviceSupport.INSTANCE.adreno()) {
+            Log.i(TAG, "no bundled driver for this GPU; using system Vulkan");
+            return null;
+        }
         String model = gpuModel();
         Log.i(TAG, "gpu model: " + (model == null ? "unknown" : model));
         if (model != null) {

app/src/main/java/com/droiddeck/launcher/wayland/WaylandCompositor.java

@@ -156,8 +156,8 @@ public final class WaylandCompositor {
 
     /** Start the compositor rendering to {@code surface}. XDG_RUNTIME_DIR = an
      *  app-writable dir for the wayland socket (e.g. context.getFilesDir()).
-     *  driverPath/libraryName/nativeLibDir select the Turnip driver via adrenotools
-     *  (all null -> system libvulkan, which can't do dmabuf import). */
+     *  driverPath/libraryName/nativeLibDir select a bundled or imported driver via adrenotools
+     *  (all null -> system libvulkan; dma-buf import support depends on that device's driver). */
     public static native void nativeStartWithSurface(Surface surface, String xdgRuntimeDir,
                                                      String driverPath, String libraryName,
                                                      String nativeLibDir);