From: Pali Rohár pali@kernel.org
commit 74e1eb3b4a1ef2e564b4bdeb6e92afe844e900de upstream.
Driver's tx_empty callback should signal when the transmit shift register is empty. So when the last character has been sent.
STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which happens when the last byte is loaded into transmit shift register.
STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift register are empty.
So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty() callback function.
Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable stable@vger.kernel.org Signed-off-by: Pali Rohár pali@kernel.org Link: https://lore.kernel.org/r/20210911132017.25505-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/mvebu-uart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -163,7 +163,7 @@ static unsigned int mvebu_uart_tx_empty( st = readl(port->membase + UART_STAT); spin_unlock_irqrestore(&port->lock, flags);
- return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0; + return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0; }
static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)