drm/amd/display: Avoid setting pixel rate divider to N/A

[Why]
Pixel rate divider values should never be set to N/A (0xF) as the K1/K2
field is only 1/2 bits wide.

[How]
Set valid divider values for virtual and FRL/DP2 cases.
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Taimur Hassan <Syed.Hassan@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c

@@ -96,6 +96,13 @@ static void dccg314_set_pixel_rate_div(
 	struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
 	enum pixel_rate_div cur_k1 = PIXEL_RATE_DIV_NA, cur_k2 = PIXEL_RATE_DIV_NA;
 
+	// Don't program 0xF into the register field. Not valid since
+	// K1 / K2 field is only 1 / 2 bits wide
+	if (k1 == PIXEL_RATE_DIV_NA || k2 == PIXEL_RATE_DIV_NA) {
+		BREAK_TO_DEBUGGER();
+		return;
+	}
+
 	dccg314_get_pixel_rate_div(dccg, otg_inst, &cur_k1, &cur_k2);
 	if (k1 == cur_k1 && k2 == cur_k2)
 		return;

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.c

@@ -348,10 +348,8 @@ unsigned int dcn314_calculate_dccg_k1_k2_values(struct pipe_ctx *pipe_ctx, unsig
 	two_pix_per_container = optc2_is_two_pixels_per_containter(&stream->timing);
 	odm_combine_factor = get_odm_config(pipe_ctx, NULL);
 
-	if (pipe_ctx->stream->signal == SIGNAL_TYPE_VIRTUAL)
-		return odm_combine_factor;
-
 	if (is_dp_128b_132b_signal(pipe_ctx)) {
+		*k1_div = PIXEL_RATE_DIV_BY_1;
 		*k2_div = PIXEL_RATE_DIV_BY_1;
 	} else if (dc_is_hdmi_tmds_signal(pipe_ctx->stream->signal) || dc_is_dvi_signal(pipe_ctx->stream->signal)) {
 		*k1_div = PIXEL_RATE_DIV_BY_1;
@@ -359,7 +357,7 @@ unsigned int dcn314_calculate_dccg_k1_k2_values(struct pipe_ctx *pipe_ctx, unsig
 			*k2_div = PIXEL_RATE_DIV_BY_2;
 		else
 			*k2_div = PIXEL_RATE_DIV_BY_4;
-	} else if (dc_is_dp_signal(pipe_ctx->stream->signal)) {
+	} else if (dc_is_dp_signal(pipe_ctx->stream->signal) || dc_is_virtual_signal(pipe_ctx->stream->signal)) {
 		if (two_pix_per_container) {
 			*k1_div = PIXEL_RATE_DIV_BY_1;
 			*k2_div = PIXEL_RATE_DIV_BY_2;

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c

@@ -96,8 +96,10 @@ static void dccg32_set_pixel_rate_div(
 
 	// Don't program 0xF into the register field. Not valid since
 	// K1 / K2 field is only 1 / 2 bits wide
-	if (k1 == PIXEL_RATE_DIV_NA || k2 == PIXEL_RATE_DIV_NA)
+	if (k1 == PIXEL_RATE_DIV_NA || k2 == PIXEL_RATE_DIV_NA) {
+		BREAK_TO_DEBUGGER();
 		return;
+	}
 
 	dccg32_get_pixel_rate_div(dccg, otg_inst, &cur_k1, &cur_k2);
 	if (k1 == cur_k1 && k2 == cur_k2)

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c

@@ -1175,10 +1175,8 @@ unsigned int dcn32_calculate_dccg_k1_k2_values(struct pipe_ctx *pipe_ctx, unsign
 	two_pix_per_container = optc2_is_two_pixels_per_containter(&stream->timing);
 	odm_combine_factor = get_odm_config(pipe_ctx, NULL);
 
-	if (pipe_ctx->stream->signal == SIGNAL_TYPE_VIRTUAL)
-		return odm_combine_factor;
-
 	if (is_dp_128b_132b_signal(pipe_ctx)) {
+		*k1_div = PIXEL_RATE_DIV_BY_1;
 		*k2_div = PIXEL_RATE_DIV_BY_1;
 	} else if (dc_is_hdmi_tmds_signal(pipe_ctx->stream->signal) || dc_is_dvi_signal(pipe_ctx->stream->signal)) {
 		*k1_div = PIXEL_RATE_DIV_BY_1;