This is a note to let you know that I've just added the patch titled
tty: serial: fsl_lpuart: disable Rx/Tx DMA in lpuart32_shutdown()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tty-serial-fsl_lpuart-disable-rx-tx-dma-in-lpuart32_.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c521a78a773c4167396864209bbf0a7c95237005
Author: Sherry Sun <sherry.sun@xxxxxxx>
Date: Fri Nov 25 18:19:52 2022 +0800
tty: serial: fsl_lpuart: disable Rx/Tx DMA in lpuart32_shutdown()
[ Upstream commit 1d4bd0e4ae4ba95892bef919a8d4d3f08f122d7e ]
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>
Link: https://lore.kernel.org/r/20221125101953.18753-3-sherry.sun@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 888e01fbd9c5f..262b059e3ee11 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1791,6 +1791,11 @@ 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 |
