monitor-manager: Add support for refresh rate modes

The refresh rate mode is exposed in the DisplayConfig D-Bus interface
and is made persistent through monitors.xml.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1154>

data/dbus-interfaces/org.gnome.Mutter.DisplayConfig.xml

@@ -337,6 +337,9 @@
 	       - "is-current" (b): the mode is currently active mode
 	       - "is-preferred" (b): the mode is the preferred mode
 	       - "is-interlaced" (b): the mode is an interlaced mode
+	       - "refresh-rate-mode" (s): the refresh rate mode, either
+					  "variable" or "fixed" (absence
+					  of this means "fixed")
 	* a{sv} properties: optional properties, including:
 	    - "width-mm" (i): physical width of monitor in millimeters
 	    - "height-mm" (i): physical height of monitor in millimeters

src/backends/meta-monitor-config-store.c

@@ -163,6 +163,7 @@ typedef enum
   STATE_MONITOR_MODE_WIDTH,
   STATE_MONITOR_MODE_HEIGHT,
   STATE_MONITOR_MODE_RATE,
+  STATE_MONITOR_MODE_RATE_MODE,
   STATE_MONITOR_MODE_FLAG,
   STATE_MONITOR_UNDERSCANNING,
   STATE_MONITOR_MAXBPC,
@@ -531,6 +532,10 @@ handle_start_element (GMarkupParseContext  *context,
           {
             parser->state = STATE_MONITOR_MODE_RATE;
           }
+        else if (g_str_equal (element_name, "ratemode"))
+          {
+            parser->state = STATE_MONITOR_MODE_RATE_MODE;
+          }
         else if (g_str_equal (element_name, "flag"))
           {
             parser->state = STATE_MONITOR_MODE_FLAG;
@@ -548,6 +553,7 @@ handle_start_element (GMarkupParseContext  *context,
     case STATE_MONITOR_MODE_WIDTH:
     case STATE_MONITOR_MODE_HEIGHT:
     case STATE_MONITOR_MODE_RATE:
+    case STATE_MONITOR_MODE_RATE_MODE:
     case STATE_MONITOR_MODE_FLAG:
       {
         g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
@@ -829,6 +835,7 @@ handle_end_element (GMarkupParseContext  *context,
     case STATE_MONITOR_MODE_WIDTH:
     case STATE_MONITOR_MODE_HEIGHT:
     case STATE_MONITOR_MODE_RATE:
+    case STATE_MONITOR_MODE_RATE_MODE:
     case STATE_MONITOR_MODE_FLAG:
       {
         parser->state = STATE_MONITOR_MODE;
@@ -1342,6 +1349,27 @@ handle_text (GMarkupParseContext *context,
         return;
       }
 
+    case STATE_MONITOR_MODE_RATE_MODE:
+      {
+        if (text_equals (text, text_len, "fixed"))
+          {
+            parser->current_monitor_mode_spec->refresh_rate_mode =
+              META_CRTC_REFRESH_RATE_MODE_FIXED;
+          }
+        else if (text_equals (text, text_len, "variable"))
+          {
+            parser->current_monitor_mode_spec->refresh_rate_mode =
+              META_CRTC_REFRESH_RATE_MODE_VARIABLE;
+          }
+        else
+          {
+            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
+                         "Invalid refresh rate mode %.*s", (int) text_len, text);
+          }
+
+        return;
+      }
+
     case STATE_MONITOR_MODE_FLAG:
       {
         if (text_equals (text, text_len, "interlace"))
@@ -1598,6 +1626,9 @@ append_monitors (GString *buffer,
                               monitor_config->mode_spec->height);
       g_string_append_printf (buffer, "          <rate>%s</rate>\n",
                               rate_str);
+      if (monitor_config->mode_spec->refresh_rate_mode ==
+          META_CRTC_REFRESH_RATE_MODE_VARIABLE)
+        g_string_append_printf (buffer, "          <ratemode>variable</ratemode>\n");
       if (monitor_config->mode_spec->flags & META_CRTC_MODE_FLAG_INTERLACE)
         g_string_append_printf (buffer, "          <flag>interlace</flag>\n");
       g_string_append (buffer, "        </mode>\n");

src/backends/meta-monitor-manager.c

@@ -2140,6 +2140,11 @@ meta_monitor_manager_handle_get_current_state (MetaDBusDisplayConfig *skeleton,
             g_variant_builder_add (&mode_properties_builder, "{sv}",
                                    "is-interlaced",
                                    g_variant_new_boolean (TRUE));
+          if (meta_monitor_mode_get_refresh_rate_mode (monitor_mode) ==
+              META_CRTC_REFRESH_RATE_MODE_VARIABLE)
+            g_variant_builder_add (&mode_properties_builder, "{sv}",
+                                   "refresh-rate-mode",
+                                   g_variant_new_string ("variable"));
 
           g_variant_builder_add (&modes_builder, MODE_FORMAT,
                                  mode_id,

src/tests/meta-monitor-test-utils.c

@@ -149,12 +149,15 @@ check_monitor_mode (MetaMonitor         *monitor,
       const MetaCrtcModeInfo *crtc_mode_info =
         meta_crtc_mode_get_info (crtc_mode);
       float refresh_rate;
+      MetaCrtcRefreshRateMode refresh_rate_mode;
       MetaCrtcModeFlag flags;
 
       refresh_rate = meta_monitor_mode_get_refresh_rate (mode);
+      refresh_rate_mode = meta_monitor_mode_get_refresh_rate_mode (mode);
       flags = meta_monitor_mode_get_flags (mode);
 
       g_assert_cmpfloat (refresh_rate, ==, crtc_mode_info->refresh_rate);
+      g_assert_cmpint (refresh_rate_mode, ==, crtc_mode_info->refresh_rate_mode);
       g_assert_cmpint (flags, ==, (crtc_mode_info->flags &
                                    HANDLED_CRTC_MODE_FLAGS));
     }
@@ -437,11 +440,13 @@ meta_check_monitor_configuration (MetaContext           *context,
           int width;
           int height;
           float refresh_rate;
+          MetaCrtcRefreshRateMode refresh_rate_mode;
           MetaCrtcModeFlag flags;
           CheckMonitorModeData data;
 
           meta_monitor_mode_get_resolution (mode, &width, &height);
           refresh_rate = meta_monitor_mode_get_refresh_rate (mode);
+          refresh_rate_mode = meta_monitor_mode_get_refresh_rate_mode (mode);
           flags = meta_monitor_mode_get_flags (mode);
 
           g_debug ("Checking mode %dx%d @ %f", width, height, refresh_rate);
@@ -455,6 +460,9 @@ meta_check_monitor_configuration (MetaContext           *context,
           g_assert_cmpfloat (refresh_rate,
                              ==,
                              expect->monitors[i].modes[j].refresh_rate);
+          g_assert_cmpint (refresh_rate_mode,
+                           ==,
+                           expect->monitors[i].modes[j].refresh_rate_mode);
           g_assert_cmpint (flags,
                            ==,
                            expect->monitors[i].modes[j].flags);
@@ -652,6 +660,7 @@ meta_create_monitor_test_setup (MetaBackend          *backend,
       crtc_mode_info->width = setup->modes[i].width;
       crtc_mode_info->height = setup->modes[i].height;
       crtc_mode_info->refresh_rate = setup->modes[i].refresh_rate;
+      crtc_mode_info->refresh_rate_mode = setup->modes[i].refresh_rate_mode;
       crtc_mode_info->flags = setup->modes[i].flags;
 
       mode = g_object_new (META_TYPE_CRTC_MODE,

src/tests/meta-monitor-test-utils.h

@@ -88,6 +88,7 @@ typedef struct _MonitorTestCaseMode
   int width;
   int height;
   float refresh_rate;
+  MetaCrtcRefreshRateMode refresh_rate_mode;
   MetaCrtcModeFlag flags;
 } MonitorTestCaseMode;
 
@@ -145,6 +146,7 @@ typedef struct _MonitorTestCaseMonitorMode
   int width;
   int height;
   float refresh_rate;
+  MetaCrtcRefreshRateMode refresh_rate_mode;
   int n_scales;
   float scales[MAX_N_SCALES];
   MetaCrtcModeFlag flags;

src/tests/monitor-configs/refresh-rate-mode-fixed.xml

@@ -0,0 +1,23 @@
+<monitors version="2">
+  <configuration>
+    <logicalmonitor>
+      <x>0</x>
+      <y>0</y>
+      <primary>yes</primary>
+      <monitor>
+	<monitorspec>
+	  <connector>DP-1</connector>
+	  <vendor>MetaProduct&apos;s Inc.</vendor>
+	  <product>MetaMonitor</product>
+	  <serial>0x123456</serial>
+	</monitorspec>
+	<mode>
+	  <width>1024</width>
+	  <height>768</height>
+	  <rate>60.000495910644531</rate>
+	  <ratemode>fixed</ratemode>
+	</mode>
+      </monitor>
+    </logicalmonitor>
+  </configuration>
+</monitors>

src/tests/monitor-configs/refresh-rate-mode-variable.xml

@@ -0,0 +1,23 @@
+<monitors version="2">
+  <configuration>
+    <logicalmonitor>
+      <x>0</x>
+      <y>0</y>
+      <primary>yes</primary>
+      <monitor>
+	<monitorspec>
+	  <connector>DP-1</connector>
+	  <vendor>MetaProduct&apos;s Inc.</vendor>
+	  <product>MetaMonitor</product>
+	  <serial>0x123456</serial>
+	</monitorspec>
+	<mode>
+	  <width>1024</width>
+	  <height>768</height>
+	  <rate>60.000495910644531</rate>
+	  <ratemode>variable</ratemode>
+	</mode>
+      </monitor>
+    </logicalmonitor>
+  </configuration>
+</monitors>

src/tests/monitor-store-unit-tests.c

@@ -37,6 +37,7 @@ typedef struct _MonitorStoreTestCaseMonitorMode
   int width;
   int height;
   float refresh_rate;
+  MetaCrtcRefreshRateMode refresh_rate_mode;
   MetaCrtcModeFlag flags;
 } MonitorStoreTestCaseMonitorMode;
 
@@ -192,6 +193,9 @@ check_monitor_store_configuration (MetaMonitorConfigStore        *config_store,
           g_assert_cmpfloat (monitor_config->mode_spec->refresh_rate,
                              ==,
                              test_monitor->mode.refresh_rate);
+          g_assert_cmpint (monitor_config->mode_spec->refresh_rate_mode,
+                           ==,
+                           test_monitor->mode.refresh_rate_mode);
           g_assert_cmpint (monitor_config->mode_spec->flags,
                            ==,
                            test_monitor->mode.flags);
@@ -463,6 +467,98 @@ meta_test_monitor_store_underscanning (void)
   check_monitor_store_configurations (&expect);
 }
 
+static void
+meta_test_monitor_store_refresh_rate_mode_fixed (void)
+{
+  MonitorStoreTestExpect expect = {
+    .configurations = {
+      {
+        .logical_monitors = {
+          {
+            .layout = {
+              .x = 0,
+              .y = 0,
+              .width = 1024,
+              .height = 768
+            },
+            .scale = 1,
+            .is_primary = TRUE,
+            .is_presentation = FALSE,
+            .monitors = {
+              {
+                .connector = "DP-1",
+                .vendor = "MetaProduct's Inc.",
+                .product = "MetaMonitor",
+                .serial = "0x123456",
+                .mode = {
+                  .width = 1024,
+                  .height = 768,
+                  .refresh_rate = 60.000495910644531,
+                  .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_FIXED,
+                },
+                .rgb_range = META_OUTPUT_RGB_RANGE_AUTO,
+              }
+            },
+            .n_monitors = 1,
+          },
+        },
+        .n_logical_monitors = 1
+      }
+    },
+    .n_configurations = 1
+  };
+
+  meta_set_custom_monitor_config (test_context, "refresh-rate-mode-fixed.xml");
+
+  check_monitor_store_configurations (&expect);
+}
+
+static void
+meta_test_monitor_store_refresh_rate_mode_variable (void)
+{
+  MonitorStoreTestExpect expect = {
+    .configurations = {
+      {
+        .logical_monitors = {
+          {
+            .layout = {
+              .x = 0,
+              .y = 0,
+              .width = 1024,
+              .height = 768
+            },
+            .scale = 1,
+            .is_primary = TRUE,
+            .is_presentation = FALSE,
+            .monitors = {
+              {
+                .connector = "DP-1",
+                .vendor = "MetaProduct's Inc.",
+                .product = "MetaMonitor",
+                .serial = "0x123456",
+                .mode = {
+                  .width = 1024,
+                  .height = 768,
+                  .refresh_rate = 60.000495910644531,
+                  .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+                },
+                .rgb_range = META_OUTPUT_RGB_RANGE_AUTO,
+              }
+            },
+            .n_monitors = 1,
+          },
+        },
+        .n_logical_monitors = 1
+      }
+    },
+    .n_configurations = 1
+  };
+
+  meta_set_custom_monitor_config (test_context, "refresh-rate-mode-variable.xml");
+
+  check_monitor_store_configurations (&expect);
+}
+
 static void
 meta_test_monitor_store_max_bpc (void)
 {
@@ -1114,6 +1210,10 @@ init_monitor_store_tests (void)
                    meta_test_monitor_store_primary);
   g_test_add_func ("/backends/monitor-store/underscanning",
                    meta_test_monitor_store_underscanning);
+  g_test_add_func ("/backends/monitor-store/refresh-rate-mode-fixed",
+                   meta_test_monitor_store_refresh_rate_mode_fixed);
+  g_test_add_func ("/backends/monitor-store/refresh-rate-mode-variable",
+                   meta_test_monitor_store_refresh_rate_mode_variable);
   g_test_add_func ("/backends/monitor-store/max-bpc",
                    meta_test_monitor_store_max_bpc);
   g_test_add_func ("/backends/monitor-store/rgb-range",

src/tests/monitor-unit-tests.c

@@ -3254,6 +3254,100 @@ meta_test_monitor_underscanning_config (void)
   check_monitor_test_clients_state ();
 }
 
+static void
+meta_test_monitor_refresh_rate_mode_config (void)
+{
+  MonitorTestCase test_case = {
+    .setup = {
+      .modes = {
+        {
+          .width = 1024,
+          .height = 768,
+          .refresh_rate = 60.0,
+          .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+        }
+      },
+      .n_modes = 1,
+      .outputs = {
+        {
+          .crtc = 0,
+          .modes = { 0 },
+          .n_modes = 1,
+          .preferred_mode = 0,
+          .possible_crtcs = { 0 },
+          .n_possible_crtcs = 1,
+          .width_mm = 222,
+          .height_mm = 125,
+        }
+      },
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0
+        }
+      },
+      .n_crtcs = 1
+    },
+
+    .expect = {
+      .monitors = {
+        {
+          .outputs = { 0 },
+          .n_outputs = 1,
+          .modes = {
+            {
+              .width = 1024,
+              .height = 768,
+              .refresh_rate = 60.0,
+              .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+              .crtc_modes = {
+                {
+                  .output = 0,
+                  .crtc_mode = 0
+                }
+              }
+            }
+          },
+          .n_modes = 1,
+          .current_mode = 0,
+          .width_mm = 222,
+          .height_mm = 125,
+        }
+      },
+      .n_monitors = 1,
+      .logical_monitors = {
+        {
+          .monitors = { 0 },
+          .n_monitors = 1,
+          .layout = { .x = 0, .y = 0, .width = 1024, .height = 768 },
+          .scale = 1
+        }
+      },
+      .n_logical_monitors = 1,
+      .primary_logical_monitor = 0,
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0,
+        }
+      },
+      .n_crtcs = 1,
+      .screen_width = 1024,
+      .screen_height = 768
+    }
+  };
+  MetaMonitorTestSetup *test_setup;
+
+  test_setup = meta_create_monitor_test_setup (test_backend,
+                                               &test_case.setup,
+                                               MONITOR_TEST_FLAG_NO_STORED);
+  emulate_hotplug (test_setup);
+  META_TEST_LOG_CALL ("Checking monitor configuration",
+                      meta_check_monitor_configuration (test_context,
+                                                        &test_case.expect));
+  check_monitor_test_clients_state ();
+}
+
 static void
 meta_test_monitor_max_bpc_config (void)
 {
@@ -5933,6 +6027,203 @@ meta_test_monitor_custom_underscanning_config (void)
   check_monitor_test_clients_state ();
 }
 
+static void
+meta_test_monitor_custom_refresh_rate_mode_fixed_config (void)
+{
+  MonitorTestCase test_case = {
+    .setup = {
+      .modes = {
+        {
+          .width = 1024,
+          .height = 768,
+          .refresh_rate = 60.000495910644531,
+          .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_FIXED,
+        }
+      },
+      .n_modes = 1,
+      .outputs = {
+        {
+          .crtc = 0,
+          .modes = { 0 },
+          .n_modes = 1,
+          .preferred_mode = 0,
+          .possible_crtcs = { 0 },
+          .n_possible_crtcs = 1,
+          .width_mm = 222,
+          .height_mm = 125,
+          .serial = "0x123456",
+        },
+      },
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0
+        },
+      },
+      .n_crtcs = 1
+    },
+
+    .expect = {
+      .monitors = {
+        {
+          .outputs = { 0 },
+          .n_outputs = 1,
+          .modes = {
+            {
+              .width = 1024,
+              .height = 768,
+              .refresh_rate = 60.000495910644531,
+              .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_FIXED,
+              .crtc_modes = {
+                {
+                  .output = 0,
+                  .crtc_mode = 0
+                }
+              }
+            }
+          },
+          .n_modes = 1,
+          .current_mode = 0,
+          .width_mm = 222,
+          .height_mm = 125,
+        }
+      },
+      .n_monitors = 1,
+      .logical_monitors = {
+        {
+          .monitors = { 0 },
+          .n_monitors = 1,
+          .layout = { .x = 0, .y = 0, .width = 1024, .height = 768 },
+          .scale = 1
+        }
+      },
+      .n_logical_monitors = 1,
+      .primary_logical_monitor = 0,
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0,
+        }
+      },
+      .n_crtcs = 1,
+      .n_tiled_monitors = 0,
+      .screen_width = 1024,
+      .screen_height = 768
+    }
+  };
+  MetaMonitorTestSetup *test_setup;
+
+  test_setup = meta_create_monitor_test_setup (test_backend,
+                                               &test_case.setup,
+                                               MONITOR_TEST_FLAG_NONE);
+  meta_set_custom_monitor_config (test_context, "refresh-rate-mode-fixed.xml");
+  emulate_hotplug (test_setup);
+
+  META_TEST_LOG_CALL ("Checking monitor configuration",
+                      meta_check_monitor_configuration (test_context,
+                                                        &test_case.expect));
+  check_monitor_test_clients_state ();
+}
+
+
+static void
+meta_test_monitor_custom_refresh_rate_mode_variable_config (void)
+{
+  MonitorTestCase test_case = {
+    .setup = {
+      .modes = {
+        {
+          .width = 1024,
+          .height = 768,
+          .refresh_rate = 60.000495910644531,
+          .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+        }
+      },
+      .n_modes = 1,
+      .outputs = {
+        {
+          .crtc = 0,
+          .modes = { 0 },
+          .n_modes = 1,
+          .preferred_mode = 0,
+          .possible_crtcs = { 0 },
+          .n_possible_crtcs = 1,
+          .width_mm = 222,
+          .height_mm = 125,
+          .serial = "0x123456",
+        },
+      },
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0
+        },
+      },
+      .n_crtcs = 1
+    },
+
+    .expect = {
+      .monitors = {
+        {
+          .outputs = { 0 },
+          .n_outputs = 1,
+          .modes = {
+            {
+              .width = 1024,
+              .height = 768,
+              .refresh_rate = 60.000495910644531,
+              .refresh_rate_mode = META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+              .crtc_modes = {
+                {
+                  .output = 0,
+                  .crtc_mode = 0
+                }
+              }
+            }
+          },
+          .n_modes = 1,
+          .current_mode = 0,
+          .width_mm = 222,
+          .height_mm = 125,
+        }
+      },
+      .n_monitors = 1,
+      .logical_monitors = {
+        {
+          .monitors = { 0 },
+          .n_monitors = 1,
+          .layout = { .x = 0, .y = 0, .width = 1024, .height = 768 },
+          .scale = 1
+        }
+      },
+      .n_logical_monitors = 1,
+      .primary_logical_monitor = 0,
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0,
+        }
+      },
+      .n_crtcs = 1,
+      .n_tiled_monitors = 0,
+      .screen_width = 1024,
+      .screen_height = 768
+    }
+  };
+  MetaMonitorTestSetup *test_setup;
+
+  test_setup = meta_create_monitor_test_setup (test_backend,
+                                               &test_case.setup,
+                                               MONITOR_TEST_FLAG_NONE);
+  meta_set_custom_monitor_config (test_context, "refresh-rate-mode-variable.xml");
+  emulate_hotplug (test_setup);
+
+  META_TEST_LOG_CALL ("Checking monitor configuration",
+                      meta_check_monitor_configuration (test_context,
+                                                        &test_case.expect));
+  check_monitor_test_clients_state ();
+}
+
 static void
 meta_test_monitor_custom_scale_config (void)
 {
@@ -9718,6 +10009,8 @@ init_monitor_tests (void)
                     meta_test_monitor_no_outputs);
   add_monitor_test ("/backends/monitor/underscanning-config",
                     meta_test_monitor_underscanning_config);
+  add_monitor_test ("/backends/monitor/refresh-rate-mode-config",
+                    meta_test_monitor_refresh_rate_mode_config);
   add_monitor_test ("/backends/monitor/max-bpc-config",
                     meta_test_monitor_max_bpc_config);
   add_monitor_test ("/backends/monitor/rgb-range-config",
@@ -9754,6 +10047,10 @@ init_monitor_tests (void)
                     meta_test_monitor_custom_primary_config);
   add_monitor_test ("/backends/monitor/custom/underscanning-config",
                     meta_test_monitor_custom_underscanning_config);
+  add_monitor_test ("/backends/monitor/custom/refresh-rate-mode-fixed-config",
+                    meta_test_monitor_custom_refresh_rate_mode_fixed_config);
+  add_monitor_test ("/backends/monitor/custom/refresh-rate-mode-variable-config",
+                    meta_test_monitor_custom_refresh_rate_mode_variable_config);
   add_monitor_test ("/backends/monitor/custom/scale-config",
                     meta_test_monitor_custom_scale_config);
   add_monitor_test ("/backends/monitor/custom/fractional-scale-config",