From 06e91df16f3e1ca1a1886968fb22d4258f3b6b6f Mon Sep 17 00:00:00 2001 From: Sherry Sun Date: Thu, 29 Jul 2021 16:31:09 +0800 Subject: [PATCH] tty: serial: fsl_lpuart: fix the wrong return value in lpuart32_get_mctrl Patch e60c2991f18b make the lpuart32_get_mctrl always return 0, actually this will break the functions of device which use flow control such as Bluetooth. For lpuart32 plaform, the hardware can handle the CTS automatically. So we should set TIOCM_CTS active. Also need to set CAR and DSR active. Patch has been tested on lpuart32 platforms such as imx8qm and imx8ulp. Fixes: e60c2991f18b ("serial: fsl_lpuart: remove RTSCTS handling from get_mctrl()") Cc: stable Signed-off-by: Sherry Sun Link: https://lore.kernel.org/r/20210729083109.31541-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman --- 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 508128d..f0e5da7 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1415,7 +1415,7 @@ static unsigned int lpuart_get_mctrl(struct uart_port *port) static unsigned int lpuart32_get_mctrl(struct uart_port *port) { - unsigned int mctrl = 0; + unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; u32 reg; reg = lpuart32_read(port, UARTCTRL); -- 2.7.4