Merge branch '2019-01-14-master-imports'

- MediaTek improvements (eth support)
- DM conversion for HI6220
- ISEE, Toby Churchill, other platform updates
- Various format code printf fixes
- Build race fixes
- Command repeat functionality enhanced, command autocomplete support
  enhanced.

2 files changed, 31 insertions, 2 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index b7ff2960ab..887cd687c0 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -442,10 +442,23 @@ config DEBUG_UART_ANNOUNCE
 
 config DEBUG_UART_SKIP_INIT
 	bool "Skip UART initialization"
+	depends on DEBUG_UART
 	help
 	  Select this if the UART you want to use for debug output is already
 	  initialized by the time U-Boot starts its execution.
 
+config DEBUG_UART_NS16550_CHECK_ENABLED
+	bool "Check if UART is enabled on output"
+	depends on DEBUG_UART
+	depends on DEBUG_UART_NS16550
+	help
+	  Select this if puts()/putc() might be called before the debug UART
+	  has been initialized. If this is disabled, putc() might sit in a
+	  tight loop if it is called before debug_uart_init() has been called.
+
+	  Note that this does not work for every ns16550-compatible UART and
+	  so has to be enabled carefully or you might notice lost characters.
+
 config ALTERA_JTAG_UART
 	bool "Altera JTAG UART support"
 	depends on DM_SERIAL
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 560ca2ae34..6cf2be8f2b 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -272,12 +272,28 @@ static inline void _debug_uart_init(void)
 	serial_dout(&com_port->lcr, UART_LCRVAL);
 }
 
+static inline int NS16550_read_baud_divisor(struct NS16550 *com_port)
+{
+	int ret;
+
+	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
+	ret = serial_din(&com_port->dll) & 0xff;
+	ret |= (serial_din(&com_port->dlm) & 0xff) << 8;
+	serial_dout(&com_port->lcr, UART_LCRVAL);
+
+	return ret;
+}
+
 static inline void _debug_uart_putc(int ch)
 {
 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 
-	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
-		;
+	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE)) {
+#ifdef CONFIG_DEBUG_UART_NS16550_CHECK_ENABLED
+		if (!NS16550_read_baud_divisor(com_port))
+			return;
+#endif
+	}
 	serial_dout(&com_port->thr, ch);
 }