Hallo Hector, On Wed, Oct 02, 2013 at 02:02:43PM +0200, Hector Palacios wrote: > When DMA is enabled (with hardware flow control enabled) the FIFO size > must be set to the size of the DMA buffer, as this is the size the tty > subsystem can use. > > Signed-off-by: Hector Palacios <hector.palacios@xxxxxxxx> > --- > drivers/tty/serial/mxs-auart.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c > index f85b8e6..9f046177 100644 > --- a/drivers/tty/serial/mxs-auart.c > +++ b/drivers/tty/serial/mxs-auart.c > @@ -40,6 +40,7 @@ > #include <asm/cacheflush.h> > > #define MXS_AUART_PORTS 5 > +#define MXS_AUART_FIFO_SIZE 16 > > #define AUART_CTRL0 0x00000000 > #define AUART_CTRL0_SET 0x00000004 > @@ -549,6 +550,9 @@ static int mxs_auart_dma_init(struct mxs_auart_port *s) > s->flags |= MXS_AUART_DMA_ENABLED; > dev_dbg(s->dev, "enabled the DMA support."); > > + /* The DMA buffer is now the FIFO the TTY subsystem can use */ > + s->port.fifosize = UART_XMIT_SIZE; > + > return 0; > > err_out: > @@ -741,6 +745,9 @@ static int mxs_auart_startup(struct uart_port *u) > writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN, > u->membase + AUART_INTR); > > + /* Reset FIFO size (it could have changed if DMA was enabled) */ > + u->fifosize = MXS_AUART_FIFO_SIZE; > + > /* > * Enable fifo so all four bytes of a DMA word are written to > * output (otherwise, only the LSB is written, ie. 1 in 4 bytes) > @@ -1062,7 +1069,7 @@ static int mxs_auart_probe(struct platform_device *pdev) > s->port.membase = ioremap(r->start, resource_size(r)); > s->port.ops = &mxs_auart_ops; > s->port.iotype = UPIO_MEM; > - s->port.fifosize = 16; > + s->port.fifosize = MXS_AUART_FIFO_SIZE; > s->port.uartclk = clk_get_rate(s->clk); > s->port.type = PORT_IMX; > s->port.dev = s->dev = &pdev->dev; I don't know if something is surprised when fifosize is changed by set_termios, but that's how it is. So: Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
