drm/amd/display: Unify all scaling when Integer Scaling enabled

[why]
We want to guarantee integer ratio scaling for all scaling modes.

[how]
Treat centered, fullscreen, preserve aspect ratio the same: scale
the view as many times as possible, and fill in the rest with a black
border.
Signed-off-by: NReza Amini <Reza.Amini@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NBhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -1552,7 +1552,10 @@ static enum surface_update_type get_scaling_info_update_type(
 	if (u->scaling_info->clip_rect.width != u->surface->clip_rect.width
 			|| u->scaling_info->clip_rect.height != u->surface->clip_rect.height
 			|| u->scaling_info->dst_rect.width != u->surface->dst_rect.width
-			|| u->scaling_info->dst_rect.height != u->surface->dst_rect.height) {
+			|| u->scaling_info->dst_rect.height != u->surface->dst_rect.height
+			|| u->scaling_info->scaling_quality.integer_scaling !=
+				u->surface->scaling_quality.integer_scaling
+			) {
 		update_flags->bits.scaling_change = 1;
 
 		if ((u->scaling_info->dst_rect.width < u->surface->dst_rect.width
@@ -1673,7 +1676,8 @@ static enum surface_update_type check_update_surfaces_for_stream(
 		union stream_update_flags *su_flags = &stream_update->stream->update_flags;
 
 		if ((stream_update->src.height != 0 && stream_update->src.width != 0) ||
-				(stream_update->dst.height != 0 && stream_update->dst.width != 0))
+			(stream_update->dst.height != 0 && stream_update->dst.width != 0) ||
+			stream_update->integer_scaling_update)
 			su_flags->bits.scaling = 1;
 
 		if (stream_update->out_transfer_func)

drivers/gpu/drm/amd/display/dc/core/dc_resource.c

@@ -951,25 +951,14 @@ static void calculate_inits_and_adj_vp(struct pipe_ctx *pipe_ctx)
 	data->inits.v_c_bot = dc_fixpt_add(data->inits.v_c, data->ratios.vert_c);
 
 }
-static bool are_rects_integer_multiples(struct rect src, struct rect dest)
-{
-	if (dest.width  >= src.width  && dest.width  % src.width  == 0 &&
-		dest.height >= src.height && dest.height % src.height == 0)
-		return true;
-
-	return false;
-}
 
 static void calculate_integer_scaling(struct pipe_ctx *pipe_ctx)
 {
-	if (!pipe_ctx->plane_state->scaling_quality.integer_scaling)
-		return;
+	unsigned int integer_multiple = 1;
 
-	//for Centered Mode
-	if (pipe_ctx->stream->dst.width  == pipe_ctx->stream->src.width &&
-		pipe_ctx->stream->dst.height == pipe_ctx->stream->src.height) {
+	if (pipe_ctx->plane_state->scaling_quality.integer_scaling) {
 		// calculate maximum # of replication of src onto addressable
-		unsigned int integer_multiple = min(
+		integer_multiple = min(
 				pipe_ctx->stream->timing.h_addressable / pipe_ctx->stream->src.width,
 				pipe_ctx->stream->timing.v_addressable  / pipe_ctx->stream->src.height);
 
@@ -980,10 +969,8 @@ static void calculate_integer_scaling(struct pipe_ctx *pipe_ctx)
 		//center dst onto addressable
 		pipe_ctx->stream->dst.x = (pipe_ctx->stream->timing.h_addressable - pipe_ctx->stream->dst.width)/2;
 		pipe_ctx->stream->dst.y = (pipe_ctx->stream->timing.v_addressable - pipe_ctx->stream->dst.height)/2;
-	}
 
-	//disable taps if src & dst are integer ratio
-	if (are_rects_integer_multiples(pipe_ctx->stream->src, pipe_ctx->stream->dst)) {
+		//We are guaranteed that we are scaling in integer ratio
 		pipe_ctx->plane_state->scaling_quality.v_taps = 1;
 		pipe_ctx->plane_state->scaling_quality.h_taps = 1;
 		pipe_ctx->plane_state->scaling_quality.v_taps_c = 1;

drivers/gpu/drm/amd/display/dc/dc_stream.h

@@ -252,6 +252,7 @@ struct dc_stream_update {
 	struct dc_info_packet *vsp_infopacket;
 
 	bool *dpms_off;
+	bool integer_scaling_update;
 
 	struct colorspace_transform *gamut_remap;
 	enum dc_color_space *output_color_space;