This is a note to let you know that I've just added the patch titled
tty: serial: fsl_lpuart: Fix the wrong RXWATER setting for rx dma case
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-fix-the-wrong-rxwater-setting-.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 467be45648519d632220610219bd9de6da5042b9
Author: Sherry Sun <sherry.sun@xxxxxxx>
Date: Mon Jan 30 14:44:46 2023 +0800
tty: serial: fsl_lpuart: Fix the wrong RXWATER setting for rx dma case
[ Upstream commit 9ad9df8447547febe9dd09b040f4528a09e495f0 ]
The RXWATER value must be greater than 0 according to the LPUART
reference manual. And when the number of datawords in the receive
FIFO is greater than RXWATER, an interrupt or a DMA request is
generated, so no need to set the different value for lpuart interrupt
case and dma case. Here delete the wrong RXWATER setting for dma case
directly.
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/20230130064449.9564-4-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 110c8720af47a..f6ac46879dc7b 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1684,12 +1684,6 @@ static void lpuart32_configure(struct lpuart_port *sport)
{
unsigned long temp;
- if (sport->lpuart_dma_rx_use) {
- /* RXWATER must be 0 */
- temp = lpuart32_read(&sport->port, UARTWATER);
- temp &= ~(UARTWATER_WATER_MASK << UARTWATER_RXWATER_OFF);
- lpuart32_write(&sport->port, temp, UARTWATER);
- }
temp = lpuart32_read(&sport->port, UARTCTRL);
if (!sport->lpuart_dma_rx_use)
temp |= UARTCTRL_RIE;
