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;