drm/amd/display: SW cursor fallback for SubVP

[Description]
Leverage SW cursor fall back for SubVP when the cursor is too big. We
want to take advantage of being able to fallback to SW cursor when
possible because it's not worth it to disable MCLK switching because the
cursor is slightly too big.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Aurabindo Pillai <Aurabindo.Pillai@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -328,6 +328,11 @@ bool dc_stream_set_cursor_attributes(
 	}
 
 	dc = stream->ctx->dc;
+
+	if (dc->debug.allow_sw_cursor_fallback && attributes->height * attributes->width * 4 > 16384)
+		if (stream->mall_stream_config.type == SUBVP_MAIN)
+			return false;
+
 	stream->cursor_attributes = *attributes;
 
 	dc_z10_restore(dc);

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

@@ -745,6 +745,7 @@ struct dc_debug_options {
 	bool disable_fixed_vs_aux_timeout_wa;
 	bool force_disable_subvp;
 	bool force_subvp_mclk_switch;
+	bool allow_sw_cursor_fallback;
 	bool force_usr_allow;
 	/* uses value at boot and disables switch */
 	bool disable_dtb_ref_clk_switch;

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c

@@ -871,6 +871,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.exit_idle_opt_for_cursor_updates = true,
 	.enable_single_display_2to1_odm_policy = true,
 	.enable_dp_dig_pixel_rate_div_policy = 1,
+	.allow_sw_cursor_fallback = false,
 };
 
 static const struct dc_debug_options debug_defaults_diags = {

drivers/gpu/drm/amd/display/dc/dcn321/dcn321_resource.c

@@ -872,6 +872,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.exit_idle_opt_for_cursor_updates = true,
 	.enable_single_display_2to1_odm_policy = true,
 	.enable_dp_dig_pixel_rate_div_policy = 1,
+	.allow_sw_cursor_fallback = false,
 };
 
 static const struct dc_debug_options debug_defaults_diags = {