Bug 1836021 [Linux] Probe VA-API devices if HW acceleration is force enabled r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D180177

toolkit/mozapps/extensions/test/xpcshell/rs-blocklist/test_gfxBlacklist_Version.js

@@ -154,9 +154,13 @@ async function run_test() {
       failureId
     );
     if (OS == "Linux" && status != Ci.nsIGfxInfo.FEATURE_STATUS_OK) {
-      // Disabled on testsuite due to old Mesa version there.
-      Assert.equal(status, Ci.nsIGfxInfo.FEATURE_BLOCKED_DRIVER_VERSION);
-      Assert.equal(failureId.value, "FEATURE_HARDWARE_VIDEO_DECODING_MESA");
+      // Linux test suite is running on SW OpenGL backend and we disable
+      // HW video decoding there.
+      Assert.equal(status, Ci.nsIGfxInfo.FEATURE_BLOCKED_PLATFORM_TEST);
+      Assert.equal(
+        failureId.value,
+        "FEATURE_FAILURE_VIDEO_DECODING_TEST_FAILED"
+      );
     } else {
       Assert.equal(status, Ci.nsIGfxInfo.FEATURE_STATUS_OK);
     }

widget/gtk/GfxInfo.cpp

@@ -24,6 +24,7 @@
 #include "mozilla/XREAppData.h"
 #include "mozilla/ScopeExit.h"
 #include "mozilla/GUniquePtr.h"
+#include "mozilla/StaticPrefs_media.h"
 #include "nsCRTGlue.h"
 #include "nsExceptionHandler.h"
 #include "nsPrintfCString.h"
@@ -1282,9 +1283,19 @@ nsresult GfxInfo::GetFeatureStatusImpl(
       aFeature, aStatus, aSuggestedDriverVersion, aDriverInfo, aFailureId, &os);
 
   // Probe VA-API/V4L2 on supported devices only
-  if (aFeature == nsIGfxInfo::FEATURE_HARDWARE_VIDEO_DECODING &&
-      *aStatus == nsIGfxInfo::FEATURE_STATUS_OK) {
-    if (mIsAccelerated) {
+  if (aFeature == nsIGfxInfo::FEATURE_HARDWARE_VIDEO_DECODING) {
+    if (!StaticPrefs::media_hardware_video_decoding_enabled_AtStartup()) {
+      return ret;
+    }
+    bool probeHWDecode = false;
+#ifdef MOZ_WAYLAND
+    probeHWDecode =
+        mIsAccelerated &&
+        (*aStatus == nsIGfxInfo::FEATURE_STATUS_OK ||
+         StaticPrefs::media_hardware_video_decoding_force_enabled_AtStartup() ||
+         StaticPrefs::media_ffmpeg_vaapi_enabled_AtStartup());
+#endif
+    if (probeHWDecode) {
       GetDataVAAPI();
       GetDataV4L2();
     } else {