[PATCH 5.11 147/601] serial: stm32: fix startup by enabling usart for reception

Greg Kroah-Hartman
2021-05-12T17:13:14Z

From: Erwan Le Ray <erwan.leray@foss.st.com>

[ Upstream commit f4518a8a75f5be1a121b0c95ad9c6b1eb27d920e ]

RX is configured, but usart is not enabled in startup function.
Kernel documentation specifies that startup should enable the port for
reception.
Fix the startup by enabling usart for reception.

Fixes: 84872dc448fe ("serial: stm32: add RX and TX FIFO flush")
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Link: https://lore.kernel.org/r/20210304162308.8984-3-erwan.leray@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/stm32-usart.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 1f7fe285bb1f..909a0d991ba1 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -633,6 +633,7 @@ static int stm32_usart_startup(struct uart_port *port)
{
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+ const struct stm32_usart_config *cfg = &stm32_port->info->cfg;
const char *name = to_platform_device(port->dev)->name;
u32 val;
int ret;
@@ -657,7 +658,7 @@ static int stm32_usart_startup(struct uart_port *port)
}

/* RX FIFO enabling */
- val = stm32_port->cr1_irq | USART_CR1_RE;
+ val = stm32_port->cr1_irq | USART_CR1_RE | BIT(cfg->uart_enable_bit);
if (stm32_port->fifoen)
val |= USART_CR1_FIFOEN;
stm32_usart_set_bits(port, ofs->cr1, val);
--
2.30.2