openwrtv3/target/linux/ar7/patches-4.1/500-serial_kludge.patch

--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -347,6 +347,13 @@ configured less than Maximum supported f
 		.rxtrig_bytes	= {1, 4, 8, 14},
 		.flags		= UART_CAP_FIFO,
 	},
+	[PORT_AR7] = {
+		.name		= "TI-AR7",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
 };
 
 /* Uart divisor latch read */
@@ -3342,7 +3349,11 @@ static void serial8250_console_putchar(s
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
+#ifdef CONFIG_AR7
+	wait_for_xmitr(up, BOTH_EMPTY);
+#else
 	wait_for_xmitr(up, UART_LSR_THRE);
+#endif
 	serial_port_out(port, UART_TX, ch);
 }