From: Sherry Sun <sherry.sun@xxxxxxx> [ 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> --- drivers/tty/serial/fsl_lpuart.c | 6 ------ 1 file changed, 6 deletions(-) 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; -- 2.39.2