--- zzzz-none-000/linux-3.10.107/arch/m68k/atari/debug.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/m68k/atari/debug.c	2021-02-04 17:41:59.000000000 +0000
@@ -287,6 +287,8 @@
 
 static int __init atari_debug_setup(char *arg)
 {
+	bool registered;
+
 	if (!MACH_IS_ATARI)
 		return 0;
 
@@ -294,6 +296,7 @@
 		/* defaults to ser2 for a Falcon and ser1 otherwise */
 		arg = MACH_IS_FALCON ? "ser2" : "ser1";
 
+	registered = !!atari_console_driver.write;
 	if (!strcmp(arg, "ser1")) {
 		/* ST-MFP Modem1 serial port */
 		atari_init_mfp_port(B9600|CS8);
@@ -317,7 +320,7 @@
 		sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
 		atari_console_driver.write = atari_par_console_write;
 	}
-	if (atari_console_driver.write)
+	if (atari_console_driver.write && !registered)
 		register_console(&atari_console_driver);
 
 	return 0;