serial: stm32: fix startup by enabling usart for reception

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>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 3d58824..c6ca8f9 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -634,6 +634,7 @@ 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;
@@ -658,7 +659,7 @@ 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);