From: Jiri Slaby <jslaby@xxxxxxx> [ Upstream commit d9c128117da41cf4cb0e80ae565b5d3ac79dffac ] The "stop TX" path in altera_uart_tx_chars() is open-coded, so: * use uart_circ_empty() to check if the buffer is empty, and * when true, call altera_uart_stop_tx(). Cc: Tobias Klauser <tklauser@xxxxxxxxxx> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Acked-by: Tobias Klauser <tklauser@xxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> Link: https://lore.kernel.org/r/20220920052049.20507-3-jslaby@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/tty/serial/altera_uart.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c index 0e487ce091ac..508a3c2b7781 100644 --- a/drivers/tty/serial/altera_uart.c +++ b/drivers/tty/serial/altera_uart.c @@ -274,10 +274,8 @@ static void altera_uart_tx_chars(struct altera_uart *pp) if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); - if (xmit->head == xmit->tail) { - pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK; - altera_uart_update_ctrl_reg(pp); - } + if (uart_circ_empty(xmit)) + altera_uart_stop_tx(port); } static irqreturn_t altera_uart_interrupt(int irq, void *data) -- 2.35.1
