Revert "serial: Delete dead code for CIR serial ports"

This reverts commit 1104321a7b3bb670dc614ffa7958c553e7b3b836.

The code is not dead at all and breaks winbond-cir.

Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a CIR port
lirc lirc0: lirc_dev: driver ir-lirc-codec (winbond-cir) registered at minor = 0
winbond-cir 00:03: Region 0x2f8-0x2ff already in use!
winbond-cir: probe of 00:03 failed with error -16

Signed-off-by: Sean Young <[e-mail]>
Reviewed-by: Matthias Brugger <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/8250/8250_core.c

···
 		if (up->dl_write)
 			uart->dl_write = up->dl_write;
 
-		if (serial8250_isa_config != NULL)
-			serial8250_isa_config(0, &uart->port,
-					&uart->capabilities);
+		if (uart->port.type != PORT_8250_CIR) {
+			if (serial8250_isa_config != NULL)
+				serial8250_isa_config(0, &uart->port,
+						&uart->capabilities);
 
-		ret = uart_add_one_port(&serial8250_reg, &uart->port);
-		if (ret == 0)
-			ret = uart->port.line;
+			ret = uart_add_one_port(&serial8250_reg,
+						&uart->port);
+			if (ret == 0)
+				ret = uart->port.line;
+		} else {
+			dev_info(uart->port.dev,
+				"skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
+				uart->port.iobase,
+				(unsigned long long)uart->port.mapbase,
+				uart->port.irq);
+
+			ret = 0;
+		}
 	}
 	mutex_unlock(&serial_mutex);