kms: Initialize variable refresh rate CRTC modes

When VRR is not disabled for a GPU, create two variants of every
display mode: one with fixed refresh rate and another with variable
refresh rate.

The variable refresh rate modes are not used yet. They will be used
in a following commit.

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

src/backends/meta-crtc-mode.h

@@ -44,6 +44,12 @@ typedef enum _MetaCrtcModeFlag
   META_CRTC_MODE_FLAG_MASK = 0x3fff
 } MetaCrtcModeFlag;
 
+typedef enum _MetaCrtcRefreshRateMode
+{
+  META_CRTC_REFRESH_RATE_MODE_FIXED,
+  META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+} MetaCrtcRefreshRateMode;
+
 typedef struct _MetaCrtcModeInfo
 {
   grefcount ref_count;
@@ -51,6 +57,7 @@ typedef struct _MetaCrtcModeInfo
   int width;
   int height;
   float refresh_rate;
+  MetaCrtcRefreshRateMode refresh_rate_mode;
   int64_t vblank_duration_us;
   uint32_t pixel_clock_khz;
   MetaCrtcModeFlag flags;

src/backends/native/meta-crtc-mode-kms.c

@@ -40,6 +40,7 @@ meta_crtc_mode_kms_get_kms_mode (MetaCrtcModeKms *mode_kms)
 
 MetaCrtcModeKms *
 meta_crtc_mode_kms_new (MetaKmsMode             *kms_mode,
+                        MetaCrtcRefreshRateMode  refresh_rate_mode,
                         uint64_t                 id)
 {
   const drmModeModeInfo *drm_mode = meta_kms_mode_get_drm_mode (kms_mode);
@@ -53,6 +54,8 @@ meta_crtc_mode_kms_new (MetaKmsMode *kms_mode,
   crtc_mode_info->flags = drm_mode->flags;
   crtc_mode_info->refresh_rate =
     meta_calculate_drm_mode_refresh_rate (drm_mode);
+  crtc_mode_info->refresh_rate_mode =
+    refresh_rate_mode;
   crtc_mode_info->vblank_duration_us =
     meta_calculate_drm_mode_vblank_duration_us (drm_mode);
   crtc_mode_info->pixel_clock_khz = drm_mode->clock;

src/backends/native/meta-crtc-mode-kms.h

@@ -31,4 +31,5 @@ G_DECLARE_FINAL_TYPE (MetaCrtcModeKms, meta_crtc_mode_kms,
 MetaKmsMode * meta_crtc_mode_kms_get_kms_mode (MetaCrtcModeKms *mode_kms);
 
 MetaCrtcModeKms * meta_crtc_mode_kms_new (MetaKmsMode             *kms_mode,
+                                          MetaCrtcRefreshRateMode  refresh_rate_mode,
                                           uint64_t                 id);

src/backends/native/meta-gpu-kms.c

@@ -163,7 +163,8 @@ compare_outputs (gconstpointer one,
 
 MetaCrtcMode *
 meta_gpu_kms_get_mode_from_kms_mode (MetaGpuKms              *gpu_kms,
-                                     MetaKmsMode *kms_mode)
+                                     MetaKmsMode             *kms_mode,
+                                     MetaCrtcRefreshRateMode  refresh_rate_mode)
 {
   MetaGpu *gpu = META_GPU (gpu_kms);
   GList *l;
@@ -171,9 +172,21 @@ meta_gpu_kms_get_mode_from_kms_mode (MetaGpuKms  *gpu_kms,
   for (l = meta_gpu_get_modes (gpu); l; l = l->next)
     {
       MetaCrtcModeKms *crtc_mode_kms = l->data;
+      MetaCrtcMode *crtc_mode;
+      const MetaCrtcModeInfo *crtc_mode_info;
 
-      if (meta_kms_mode_equal (kms_mode,
+      if (!meta_kms_mode_equal (kms_mode,
                                 meta_crtc_mode_kms_get_kms_mode (crtc_mode_kms)))
+        continue;
+
+      crtc_mode = META_CRTC_MODE (crtc_mode_kms);
+
+      crtc_mode_info = meta_crtc_mode_get_info (crtc_mode);
+      g_assert (crtc_mode_info != NULL);
+
+      if (refresh_rate_mode != crtc_mode_info->refresh_rate_mode)
+        continue;
+
       return META_CRTC_MODE (crtc_mode_kms);
     }
 
@@ -274,7 +287,19 @@ init_modes (MetaGpuKms *gpu_kms)
       MetaKmsMode *kms_mode = value;
       MetaCrtcModeKms *mode;
 
-      mode = meta_crtc_mode_kms_new (kms_mode, mode_id);
+      if (!meta_gpu_kms_disable_vrr (gpu_kms))
+        {
+          mode = meta_crtc_mode_kms_new (kms_mode,
+                                         META_CRTC_REFRESH_RATE_MODE_VARIABLE,
+                                         mode_id);
+          modes = g_list_append (modes, mode);
+
+          mode_id++;
+        }
+
+      mode = meta_crtc_mode_kms_new (kms_mode,
+                                     META_CRTC_REFRESH_RATE_MODE_FIXED,
+                                     mode_id);
       modes = g_list_append (modes, mode);
 
       mode_id++;

src/backends/native/meta-gpu-kms.h

@@ -57,7 +57,8 @@ void meta_gpu_kms_set_power_save_mode (MetaGpuKms    *gpu_kms,
                                        MetaKmsUpdate *kms_update);
 
 MetaCrtcMode * meta_gpu_kms_get_mode_from_kms_mode (MetaGpuKms              *gpu_kms,
-                                                    MetaKmsMode *kms_mode);
+                                                    MetaKmsMode             *kms_mode,
+                                                    MetaCrtcRefreshRateMode  refresh_rate_mode);
 
 MetaGpuKmsFlipClosureContainer * meta_gpu_kms_wrap_flip_closure (MetaGpuKms *gpu_kms,
                                                                  MetaCrtc   *crtc,

src/backends/native/meta-output-kms.c

@@ -179,7 +179,9 @@ add_common_modes (MetaOutputInfo *output_info,
       if (is_duplicate)
         continue;
 
-      crtc_mode = meta_gpu_kms_get_mode_from_kms_mode (gpu_kms, fallback_mode);
+      crtc_mode = meta_gpu_kms_get_mode_from_kms_mode (gpu_kms,
+                                                       fallback_mode,
+                                                       META_CRTC_REFRESH_RATE_MODE_FIXED);
       g_ptr_array_add (array, crtc_mode);
     }
 
@@ -280,7 +282,9 @@ init_output_modes (MetaOutputInfo    *output_info,
       MetaKmsMode *kms_mode = l->data;
       MetaCrtcMode *crtc_mode;
 
-      crtc_mode = meta_gpu_kms_get_mode_from_kms_mode (gpu_kms, kms_mode);
+      crtc_mode = meta_gpu_kms_get_mode_from_kms_mode (gpu_kms,
+                                                       kms_mode,
+                                                       META_CRTC_REFRESH_RATE_MODE_FIXED);
       output_info->modes[i] = crtc_mode;
       if (kms_mode == kms_preferred_mode)
         output_info->preferred_mode = output_info->modes[i];