Re: [PATCH 4.19 144/245] serial: uartps: Wait for tx_empty in console setup

Hi!

From: Raviteja Narayanam raviteja.narayanam@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.

@@ -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();
  

So this is spinning for half a second. Could we use msleep(1) instead of cpu_relax or something like that?

Best regards, Pavel