From 28016e1a58c0799b6afca97a96f0b13c8dfd349f Mon Sep 17 00:00:00 2001
From: Robert Mader <robert.mader@posteo.de>
Date: Wed, 2 Feb 2022 21:48:44 +0100
Subject: [PATCH] settings: Drop the dma-buf-screen-sharing experimental
 feature

It got introduced when many applications didn't handle dmabufs
with non-linear modifiers, trying to mmap and read directly from
them, giving disappointing results. By now these should be fixed
and other compositors/DEs also don't carry around similar
restrictions. Thus drop the feature and use dmabufs on every
hardware if the app requested that.

This should improve the screen sharing experience especially on
AMD systems.
---
 data/org.gnome.mutter.gschema.xml.in      |  8 +-------
 src/backends/meta-settings-private.h      |  3 +--
 src/backends/meta-settings.c              |  2 --
 src/backends/native/meta-backend-native.c | 25 +----------------------
 4 files changed, 3 insertions(+), 35 deletions(-)

diff --git a/data/org.gnome.mutter.gschema.xml.in b/data/org.gnome.mutter.gschema.xml.in
index b54170eec6a..c014b749fcf 100644
--- a/data/org.gnome.mutter.gschema.xml.in
+++ b/data/org.gnome.mutter.gschema.xml.in
@@ -4,8 +4,7 @@
     <value nick="scale-monitor-framebuffer" value="1"/>
     <value nick="kms-modifiers" value="2"/>
     <value nick="rt-scheduler" value="4"/>
-    <value nick="dma-buf-screen-sharing" value="8"/>
-    <value nick="autoclose-xwayland" value="16"/>
+    <value nick="autoclose-xwayland" value="8"/>
   </flags>
 
   <schema id="org.gnome.mutter" path="/org/gnome/mutter/"
@@ -139,11 +138,6 @@
         • “rt-scheduler”              — makes mutter request a low priority
                                         real-time scheduling. Requires a restart.
 
-        • “dma-buf-screen-sharing”    — enables DMA buffered screen sharing. This
-                                        is already enabled by default when using
-                                        the i915 driver, but disabled for 
-                                        everything else. Requires a restart.
-
         • “autoclose-xwayland”        — automatically terminates Xwayland if all
                                         relevant X11 clients are gone.
                                         Requires a restart.
diff --git a/src/backends/meta-settings-private.h b/src/backends/meta-settings-private.h
index fb9aea0dcb4..47d2d6074e3 100644
--- a/src/backends/meta-settings-private.h
+++ b/src/backends/meta-settings-private.h
@@ -34,8 +34,7 @@ typedef enum _MetaExperimentalFeature
   META_EXPERIMENTAL_FEATURE_SCALE_MONITOR_FRAMEBUFFER = (1 << 0),
   META_EXPERIMENTAL_FEATURE_KMS_MODIFIERS  = (1 << 1),
   META_EXPERIMENTAL_FEATURE_RT_SCHEDULER = (1 << 2),
-  META_EXPERIMENTAL_FEATURE_DMA_BUF_SCREEN_SHARING = (1 << 3),
-  META_EXPERIMENTAL_FEATURE_AUTOCLOSE_XWAYLAND  = (1 << 4),
+  META_EXPERIMENTAL_FEATURE_AUTOCLOSE_XWAYLAND  = (1 << 3),
 } MetaExperimentalFeature;
 
 typedef enum _MetaXwaylandExtension
diff --git a/src/backends/meta-settings.c b/src/backends/meta-settings.c
index f672026ea56..2826ff98f94 100644
--- a/src/backends/meta-settings.c
+++ b/src/backends/meta-settings.c
@@ -294,8 +294,6 @@ experimental_features_handler (GVariant *features_variant,
         feature = META_EXPERIMENTAL_FEATURE_KMS_MODIFIERS;
       else if (g_str_equal (feature_str, "rt-scheduler"))
         feature = META_EXPERIMENTAL_FEATURE_RT_SCHEDULER;
-      else if (g_str_equal (feature_str, "dma-buf-screen-sharing"))
-        feature = META_EXPERIMENTAL_FEATURE_DMA_BUF_SCREEN_SHARING;
       else if (g_str_equal (feature_str, "autoclose-xwayland"))
         feature = META_EXPERIMENTAL_FEATURE_AUTOCLOSE_XWAYLAND;
 
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index e3d2c5ab032..0f0a383c689 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -158,40 +158,17 @@ static void
 maybe_disable_screen_cast_dma_bufs (MetaBackendNative *native)
 {
   MetaBackend *backend = META_BACKEND (native);
-  MetaSettings *settings = meta_backend_get_settings (backend);
   MetaRenderer *renderer = meta_backend_get_renderer (backend);
   MetaRendererNative *renderer_native = META_RENDERER_NATIVE (renderer);
   MetaScreenCast *screen_cast = meta_backend_get_screen_cast (backend);
   MetaGpuKms *primary_gpu;
-  MetaKmsDevice *kms_device;
-  const char *driver_name;
-  static const char *enable_dma_buf_drivers[] = {
-    "i915",
-    NULL,
-  };
 
   primary_gpu = meta_renderer_native_get_primary_gpu (renderer_native);
   if (!primary_gpu)
     {
       g_message ("Disabling DMA buffer screen sharing (surfaceless)");
-      goto disable_dma_bufs;
+      meta_screen_cast_disable_dma_bufs (screen_cast);
     }
-
-  kms_device = meta_gpu_kms_get_kms_device (primary_gpu);
-  driver_name = meta_kms_device_get_driver_name (kms_device);
-
-  if (g_strv_contains (enable_dma_buf_drivers, driver_name))
-    return;
-
-  if (meta_settings_is_experimental_feature_enabled (settings,
-        META_EXPERIMENTAL_FEATURE_DMA_BUF_SCREEN_SHARING))
-    return;
-
-  g_message ("Disabling DMA buffer screen sharing for driver '%s'.",
-             driver_name);
-
-disable_dma_bufs:
-  meta_screen_cast_disable_dma_bufs (screen_cast);
 }
 #endif /* HAVE_REMOTE_DESKTOP */
 
-- 
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