From: Heikki Krogerus Date: Thu, 5 Sep 2013 14:34:52 +0000 (+0300) Subject: serial: 8250: don't change the fifo trigger level when using dma X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2797f6fb6727d8ac5127f88aee1fd059db0be24b;p=linux-beck.git serial: 8250: don't change the fifo trigger level when using dma DMA engines usually expect the fifo trigger level to be aligned with the burst size. It should not be changed even with small baud rates. This will fix an issue with Designware DMA engine where the data can not be transferred over UART with lower baud rates then 2400. Signed-off-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 570df9d2a5d2..e33d38cb170f 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -2322,7 +2322,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) { fcr = uart_config[port->type].fcr; - if (baud < 2400 || fifo_bug) { + if ((baud < 2400 && !up->dma) || fifo_bug) { fcr &= ~UART_FCR_TRIGGER_MASK; fcr |= UART_FCR_TRIGGER_1; }