From 6d0b8cc851ca4cc79ec967a1dd4c9a292f43f04e Mon Sep 17 00:00:00 2001 From: Valentin Caron Date: Tue, 11 Jan 2022 17:44:41 +0100 Subject: serial: stm32: fix software flow control transfer commit 037b91ec7729524107982e36ec4b40f9b174f7a2 upstream. x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty. Fix start_tx condition to allow x_char to be sent. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable Signed-off-by: Erwan Le Ray Signed-off-by: Valentin Caron Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/stm32-usart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial/stm32-usart.c') diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index f89d1f79be18..83d3645ac2ef 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -279,7 +279,7 @@ static void stm32_start_tx(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; - if (uart_circ_empty(xmit)) + if (uart_circ_empty(xmit) && !port->x_char) return; stm32_set_bits(port, USART_CR1, USART_CR1_TXEIE | USART_CR1_TE); -- cgit v1.2.3