1 commit 7187bba8bcfa4756d459e09b0bda192ca93b12f9
   2 Author: Mitchell Horne <mhorne@FreeBSD.org>
   3 Date:   Fri Jan 26 13:35:00 2024 -0400
   4 
   5     ns8250: workaround on VisionFive v2
   6     
   7     For some reason, writing to the data register after ns8250_probe() and
   8     before setting the baudrate prevents the garbled output.
   9 
  10 diff --git a/sys/dev/uart/uart_dev_ns8250.c b/sys/dev/uart/uart_dev_ns8250.c
  11 index f211084cb013..03d17415e87c 100644
  12 --- a/sys/dev/uart/uart_dev_ns8250.c
  13 +++ b/sys/dev/uart/uart_dev_ns8250.c
  14 @@ -281,6 +281,8 @@ ns8250_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
  15  		lcr |= LCR_STOPB;
  16  	lcr |= parity << 3;
  17  
  18 +	uart_setreg(bas, REG_DATA, 0);
  19 +
  20  	/* Set baudrate. */
  21  	if (baudrate > 0) {
  22  		divisor = ns8250_divisor(bas->rclk, baudrate);