Revert "drm/amd/display: Enable Freesync Video Mode by default"

From Michel Daenzer
d54f66bc9c371e4765d78144c8dac568a59a31dd in linux-6.1.y/6.1.5
6fe6ece398f7431784847e922a2c8c385dc58a35 in mainline linux

3 files changed, 35 insertions, 5 deletions

diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu.h b/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
index 4337508eaef..43866a7c3d6 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
@@ -200,6 +200,7 @@ extern int amdgpu_emu_mode;
 extern uint amdgpu_smu_memory_pool_size;
 extern int amdgpu_smu_pptable_id;
 extern uint amdgpu_dc_feature_mask;
+extern uint amdgpu_freesync_vid_mode;
 extern uint amdgpu_dc_debug_mask;
 extern uint amdgpu_dc_visual_confirm;
 extern uint amdgpu_dm_abm_level;
diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c
index 7ac810dc165..2824fbe6832 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c
@@ -180,6 +180,7 @@ int amdgpu_mes_kiq;
 int amdgpu_noretry = -1;
 int amdgpu_force_asic_type = -1;
 int amdgpu_tmz = -1; /* auto */
+uint amdgpu_freesync_vid_mode;
 int amdgpu_reset_method = -1; /* auto */
 int amdgpu_num_kcq = -1;
 int amdgpu_smartshift_bias;
@@ -878,6 +879,32 @@ MODULE_PARM_DESC(tmz, "Enable TMZ feature (-1 = auto (default), 0 = off, 1 = on)
 module_param_named(tmz, amdgpu_tmz, int, 0444);
 
 /**
+ * DOC: freesync_video (uint)
+ * Enable the optimization to adjust front porch timing to achieve seamless
+ * mode change experience when setting a freesync supported mode for which full
+ * modeset is not needed.
+ *
+ * The Display Core will add a set of modes derived from the base FreeSync
+ * video mode into the corresponding connector's mode list based on commonly
+ * used refresh rates and VRR range of the connected display, when users enable
+ * this feature. From the userspace perspective, they can see a seamless mode
+ * change experience when the change between different refresh rates under the
+ * same resolution. Additionally, userspace applications such as Video playback
+ * can read this modeset list and change the refresh rate based on the video
+ * frame rate. Finally, the userspace can also derive an appropriate mode for a
+ * particular refresh rate based on the FreeSync Mode and add it to the
+ * connector's mode list.
+ *
+ * Note: This is an experimental feature.
+ *
+ * The default value: 0 (off).
+ */
+MODULE_PARM_DESC(
+	freesync_video,
+	"Enable freesync modesetting optimization feature (0 = off (default), 1 = on)");
+module_param_named(freesync_video, amdgpu_freesync_vid_mode, uint, 0444);
+
+/**
  * DOC: reset_method (int)
  * GPU reset method (-1 = auto (default), 0 = legacy, 1 = mode0, 2 = mode1, 3 = mode2, 4 = baco)
  */
diff --git a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index dcc05ff8800..68fb4b90e22 100644
--- a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5815,7 +5815,8 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
 		 */
 		DRM_DEBUG_DRIVER("No preferred mode found\n");
 	} else {
-		recalculate_timing = is_freesync_video_mode(&mode, aconnector);
+		recalculate_timing = amdgpu_freesync_vid_mode &&
+				 is_freesync_video_mode(&mode, aconnector);
 		if (recalculate_timing) {
 			freesync_mode = get_highest_refresh_rate_mode(aconnector, false);
 			drm_mode_copy(&saved_mode, &mode);
@@ -6904,7 +6905,7 @@ static void amdgpu_dm_connector_add_freesync_modes(struct drm_connector *connect
 	struct amdgpu_dm_connector *amdgpu_dm_connector =
 		to_amdgpu_dm_connector(connector);
 
-	if (!edid)
+	if (!(amdgpu_freesync_vid_mode && edid))
 		return;
 
 	if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
@@ -8767,7 +8768,8 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
 		 * TODO: Refactor this function to allow this check to work
 		 * in all conditions.
 		 */
-		if (dm_new_crtc_state->stream &&
+		if (amdgpu_freesync_vid_mode &&
+		    dm_new_crtc_state->stream &&
 		    is_timing_unchanged_for_freesync(new_crtc_state, old_crtc_state))
 			goto skip_modeset;
 
@@ -8802,7 +8804,7 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
 		if (!dm_old_crtc_state->stream)
 			goto skip_modeset;
 
-		if (dm_new_crtc_state->stream &&
+		if (amdgpu_freesync_vid_mode && dm_new_crtc_state->stream &&
 		    is_timing_unchanged_for_freesync(new_crtc_state,
 						     old_crtc_state)) {
 			new_crtc_state->mode_changed = false;
@@ -8814,7 +8816,7 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
 			set_freesync_fixed_config(dm_new_crtc_state);
 
 			goto skip_modeset;
-		} else if (aconnector &&
+		} else if (amdgpu_freesync_vid_mode && aconnector &&
 			   is_freesync_video_mode(&new_crtc_state->mode,
 						  aconnector)) {
 			struct drm_display_mode *high_mode;