UARTBAUD_RDMAE and UARTBAUD_TDMAE are enabled in lpuart32_startup(), but lpuart32_shutdown() not disable them, only free the dma ring buffer and release the dma channels, so here disable the Rx/Tx DMA first in lpuart32_shutdown(). Fixes: 42b68768e51b ("serial: fsl_lpuart: DMA support for 32-bit variant") Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> --- Changes in V2: 1. Split one patch into four smaller patches to improve the commit messages and add Fixes tag as suggested by Ilpo. --- drivers/tty/serial/fsl_lpuart.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index a6f7b056d57b..c297be11422a 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1769,6 +1769,11 @@ static void lpuart32_shutdown(struct uart_port *port) spin_lock_irqsave(&port->lock, flags); + /* disable Rx/Tx DMA */ + temp = lpuart32_read(port, UARTBAUD); + temp &= ~(UARTBAUD_TDMAE | UARTBAUD_RDMAE); + lpuart32_write(port, temp, UARTBAUD); + /* disable Rx/Tx and interrupts */ temp = lpuart32_read(port, UARTCTRL); temp &= ~(UARTCTRL_TE | UARTCTRL_RE | UARTCTRL_ILIE | -- 2.17.1