From: Peng Fan peng.fan@nxp.com
commit 29788ab1d2bf26c130de8f44f9553ee78a27e8d5 upstream.
The watermark is set to 1, so we need to input two chars to trigger RDRF using the original logic. With the new logic, we could always get the char when there is data in FIFO.
Suggested-by: Fugang Duan fugang.duan@nxp.com Signed-off-by: Peng Fan peng.fan@nxp.com Link: https://lore.kernel.org/r/20200929095509.21680-1-peng.fan@nxp.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/fsl_lpuart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 2daccb10ae2f..4b9f42269477 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -563,7 +563,7 @@ static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
static int lpuart32_poll_get_char(struct uart_port *port) { - if (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_RDRF)) + if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF)) return NO_POLL_CHAR;
return lpuart32_read(port, UARTDATA);