[PATCH] serial: uartps: Add monitoring TACTIVE bit in set_termios
From: <hidden>
Date: 2020-01-07 12:00:10
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Raviteja Narayanam <redacted> Before setting up baud rate in set_termios function, make sure all the data is shifted out from the Uart transmitter by monitoring TACTIVE bit in the channel status register. Signed-off-by: Raviteja Narayanam <redacted> --- drivers/tty/serial/xilinx_uartps.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index ed2f325..c337544 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c@@ -703,11 +703,15 @@ static void cdns_uart_set_termios(struct uart_port *port, unsigned int ctrl_reg, mode_reg, val; int err; - /* Wait for the transmit FIFO to empty before making changes */ + /* Wait for the transmit FIFO to empty and Transmitter to shift out + * all the data before making changes + */ if (!(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_TX_DIS)) { err = readl_poll_timeout(port->membase + CDNS_UART_SR, - val, (val & CDNS_UART_SR_TXEMPTY), + val, ((val & (CDNS_UART_SR_TXEMPTY | + CDNS_UART_SR_TACTIVE)) == + CDNS_UART_SR_TXEMPTY), 1000, TX_TIMEOUT); if (err) { dev_err(port->dev, "timed out waiting for tx empty");
--
2.7.4