Triggering RX interrupt for every byte defeats the purpose of aging timer and leads to interrupt starvation at high baud rates. Increase receiver trigger level to 8 to increase the minimum period between RX interrupts to 8 characters time. The tradeoff is increased latency. In the worst case scenario, where RX data has intercharacter delay slightly less than aging timer (8 characters time), it can take up to 63 characters time for the interrupt to be raised since the reception of the first character. Signed-off-by: Tomasz Moń <tomasz.mon@xxxxxxxxxxxxxxx> --- drivers/tty/serial/imx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 90f82e6c54e4..3c812c47ecc0 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1255,7 +1255,7 @@ static void imx_uart_clear_rx_errors(struct imx_port *sport) } #define TXTL_DEFAULT 2 /* reset default */ -#define RXTL_DEFAULT 1 /* reset default */ +#define RXTL_DEFAULT 8 /* 8 characters or aging timer */ #define TXTL_DMA 8 /* DMA burst setting */ #define RXTL_DMA 9 /* DMA burst setting */ -- 2.25.1
