drm/amdgpu/display: re-enable freesync video patches

Since this is a "revert of a revert", the end effect is that freesync
video is back to its original state, the way it was before the first
revert.

Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -189,6 +189,7 @@ 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_dm_abm_level;
 extern int amdgpu_backlight;

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -166,6 +166,7 @@ int amdgpu_mes;
 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;
 
@@ -828,6 +829,17 @@ module_param_named(backlight, amdgpu_backlight, bint, 0444);
 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)
+ * Enabled 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 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, 5 = pci)