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serial: mxs-auart: set the FIFO size to DMA buffer size

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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@digi.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hector Palacios 2013-10-03 09:32:03 +02:00 committed by Greg Kroah-Hartman
parent 7ea816a0c3
commit 9987f76ad2
1 changed files with 8 additions and 1 deletions
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9
drivers/tty/serial/mxs-auart.c
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@ -39,6 +39,7 @@
#include <asm/cacheflush.h>
#define MXS_AUART_PORTS 5
#define MXS_AUART_FIFO_SIZE 16
#define AUART_CTRL0 0x00000000
#define AUART_CTRL0_SET 0x00000004
@ -548,6 +549,9 @@ 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)
@ -1056,7 +1063,7 @@ 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;