From: Raviteja Narayanam <raviteja.naraya...@xilinx.com>

[ Upstream commit 42e11948ddf68b9f799cad8c0ddeab0a39da33e8 ]

On some platforms, the log is corrupted while console is being
registered. It is observed that when set_termios is called, there
are still some bytes in the FIFO to be transmitted.

So, wait for tx_empty inside cdns_uart_console_setup before calling
set_termios.

Signed-off-by: Raviteja Narayanam <raviteja.naraya...@xilinx.com>
Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.da...@xilinx.com>
Link: 
https://lore.kernel.org/r/1586413563-29125-2-git-send-email-raviteja.naraya...@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/tty/serial/xilinx_uartps.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/xilinx_uartps.c 
b/drivers/tty/serial/xilinx_uartps.c
index 31950a38f0fb7..23f9b0cdff086 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1236,6 +1236,7 @@ static int cdns_uart_console_setup(struct console *co, 
char *options)
        int bits = 8;
        int parity = 'n';
        int flow = 'n';
+       unsigned long time_out;
 
        if (!port->membase) {
                pr_debug("console on " CDNS_UART_TTY_NAME "%i not present\n",
@@ -1246,6 +1247,13 @@ static int cdns_uart_console_setup(struct console *co, 
char *options)
        if (options)
                uart_parse_options(options, &baud, &parity, &bits, &flow);
 
+       /* Wait for tx_empty before setting up the console */
+       time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT);
+
+       while (time_before(jiffies, time_out) &&
+              cdns_uart_tx_empty(port) != TIOCSER_TEMT)
+               cpu_relax();
+
        return uart_set_options(port, co, baud, parity, bits, flow);
 }
 
-- 
2.25.1

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