drm/amd/display: fix underflow on boot

[Why]
New seamless boot sequence introduced a bug where front end is disabled
without blanking otg.

[How]
Adjust the condition of blanking otg to match seamless boot.
Signed-off-by: Eric Yang <Eric.Yang2@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -979,16 +979,14 @@ static void dcn10_init_pipes(struct dc *dc, struct dc_state *context)
 		 * to non-preferred front end. If pipe_ctx->stream is not NULL,
 		 * we will use the pipe, so don't disable
 		 */
-		if (pipe_ctx->stream != NULL)
+		if (pipe_ctx->stream != NULL && can_apply_seamless_boot)
 			continue;
 
-		if (tg->funcs->is_tg_enabled(tg))
-			tg->funcs->lock(tg);
-
 		/* Blank controller using driver code instead of
 		 * command table.
 		 */
 		if (tg->funcs->is_tg_enabled(tg)) {
+			tg->funcs->lock(tg);
 			tg->funcs->set_blank(tg, true);
 			hwss_wait_for_blank_complete(tg);
 		}