drm/amd/display: Fix bug where refresh rate becomes fixed

This issue occurs if refresh rate range is very small and lfc is not used.
When frame spikes occur, refresh rate becomes fixed and will not restore properly
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/modules/freesync/freesync.c

@@ -168,21 +168,6 @@ static unsigned int calc_v_total_from_duration(
 	return v_total;
 }
 
-static unsigned long long calc_nominal_field_rate(const struct dc_stream_state *stream)
-{
-	unsigned long long nominal_field_rate_in_uhz = 0;
-
-	/* Calculate nominal field rate for stream */
-	nominal_field_rate_in_uhz = stream->timing.pix_clk_khz;
-	nominal_field_rate_in_uhz *= 1000ULL * 1000ULL * 1000ULL;
-	nominal_field_rate_in_uhz = div_u64(nominal_field_rate_in_uhz,
-						stream->timing.h_total);
-	nominal_field_rate_in_uhz = div_u64(nominal_field_rate_in_uhz,
-						stream->timing.v_total);
-
-	return nominal_field_rate_in_uhz;
-}
-
 static void update_v_total_for_static_ramp(
 		struct core_freesync *core_freesync,
 		const struct dc_stream_state *stream,
@@ -441,10 +426,11 @@ static void apply_fixed_refresh(struct core_freesync *core_freesync,
 					in_out_vrr->adjust.v_total_min;
 		} else {
 			in_out_vrr->adjust.v_total_min =
-				calc_v_total_from_refresh(
-				stream, in_out_vrr->max_refresh_in_uhz);
+				calc_v_total_from_refresh(stream,
+					in_out_vrr->max_refresh_in_uhz);
 			in_out_vrr->adjust.v_total_max =
-				in_out_vrr->adjust.v_total_min;
+				calc_v_total_from_refresh(stream,
+					in_out_vrr->min_refresh_in_uhz);
 		}
 	}
 }
@@ -638,7 +624,8 @@ void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync,
 	core_freesync = MOD_FREESYNC_TO_CORE(mod_freesync);
 
 	/* Calculate nominal field rate for stream */
-	nominal_field_rate_in_uhz = calc_nominal_field_rate(stream);
+	nominal_field_rate_in_uhz =
+			mod_freesync_calc_nominal_field_rate(stream);
 
 	min_refresh_in_uhz = in_config->min_refresh_in_uhz;
 	max_refresh_in_uhz = in_config->max_refresh_in_uhz;
@@ -888,6 +875,22 @@ void mod_freesync_get_settings(struct mod_freesync *mod_freesync,
 	}
 }
 
+unsigned long long mod_freesync_calc_nominal_field_rate(
+			const struct dc_stream_state *stream)
+{
+	unsigned long long nominal_field_rate_in_uhz = 0;
+
+	/* Calculate nominal field rate for stream */
+	nominal_field_rate_in_uhz = stream->timing.pix_clk_khz;
+	nominal_field_rate_in_uhz *= 1000ULL * 1000ULL * 1000ULL;
+	nominal_field_rate_in_uhz = div_u64(nominal_field_rate_in_uhz,
+						stream->timing.h_total);
+	nominal_field_rate_in_uhz = div_u64(nominal_field_rate_in_uhz,
+						stream->timing.v_total);
+
+	return nominal_field_rate_in_uhz;
+}
+
 bool mod_freesync_is_valid_range(struct mod_freesync *mod_freesync,
 		const struct dc_stream_state *stream,
 		uint32_t min_refresh_cap_in_uhz,
@@ -897,7 +900,7 @@ bool mod_freesync_is_valid_range(struct mod_freesync *mod_freesync,
 {
 	/* Calculate nominal field rate for stream */
 	unsigned long long nominal_field_rate_in_uhz =
-			calc_nominal_field_rate(stream);
+			mod_freesync_calc_nominal_field_rate(stream);
 
 	// Check nominal is within range
 	if (nominal_field_rate_in_uhz > max_refresh_cap_in_uhz ||

drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h

@@ -159,6 +159,9 @@ void mod_freesync_handle_v_update(struct mod_freesync *mod_freesync,
 		const struct dc_stream_state *stream,
 		struct mod_vrr_params *in_out_vrr);
 
+unsigned long long mod_freesync_calc_nominal_field_rate(
+			const struct dc_stream_state *stream);
+
 bool mod_freesync_is_valid_range(struct mod_freesync *mod_freesync,
 		const struct dc_stream_state *stream,
 		uint32_t min_refresh_cap_in_uhz,