Since imx8qxp RX FIFO depth is 64 datawords, it will be better to set
the rx watermark as 31, which means when the number of datawords in the
receive FIFO(>= 32) is greater than the watermark, an interrupt or a DMA
request is generated.
Also keep the console rx watermark as 1 to make sure it responsive.
Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
drivers/tty/serial/fsl_lpuart.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index e4aa161e61bf..868c2783d2c7 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -321,7 +321,7 @@ static struct lpuart_soc_data imx8qxp_data = {
.devtype = IMX8QXP_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
- .rx_watermark = 1,
+ .rx_watermark = 31,
};
static struct lpuart_soc_data imxrt1050_data = {
.devtype = IMXRT1050_LPUART,
@@ -1527,6 +1527,8 @@ static void lpuart_setup_watermark(struct lpuart_port *sport)
writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
}
+ if (uart_console(&sport->port))
+ sport->rx_watermark = 1;
writeb(0, sport->port.membase + UARTTWFIFO);
writeb(sport->rx_watermark, sport->port.membase + UARTRWFIFO);
@@ -1563,6 +1565,8 @@ static void lpuart32_setup_watermark(struct lpuart_port *sport)
lpuart32_write(&sport->port, val, UARTFIFO);
/* set the watermark */
+ if (uart_console(&sport->port))
+ sport->rx_watermark = 1;
val = (sport->rx_watermark << UARTWATER_RXWATER_OFF) |
(0x0 << UARTWATER_TXWATER_OFF);
lpuart32_write(&sport->port, val, UARTWATER);
--
2.17.1
