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Revert "serial: imx: initialized DMA w/o HW flow enabled" 

This reverts commit 068500e08d.

According to some tests, SDMA support is broken at least for i.MX6 without
HW flow control. Different forms of data-corruption appear either with
the ROM firmware for the SDMA controller as well as when loading Freescale
provided SDMA firmware versions 1.1 or 3.1.

Signed-off-by: David Jander <david@protonic.nl>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Jander 2015-06-26 08:11:30 +02:00 committed by Greg Kroah-Hartman
parent dec273ecc1
commit 907eda32a3
1 changed files with 7 additions and 8 deletions
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15
drivers/tty/serial/imx.c
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@ -1121,11 +1121,6 @@ static int imx_startup(struct uart_port *port)
writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
/* Can we enable the DMA support? */
if (is_imx6q_uart(sport) && !uart_console(port) &&
!sport->dma_is_inited)
imx_uart_dma_init(sport);
spin_lock_irqsave(&sport->port.lock, flags);
/* Reset fifo's and state machines */
i = 100;
@ -1143,9 +1138,6 @@ static int imx_startup(struct uart_port *port)
writel(USR1_RTSD, sport->port.membase + USR1);
writel(USR2_ORE, sport->port.membase + USR2);
if (sport->dma_is_inited && !sport->dma_is_enabled)
imx_enable_dma(sport);
temp = readl(sport->port.membase + UCR1);
temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
@ -1316,6 +1308,11 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
} else {
ucr2 |= UCR2_CTSC;
}
/* Can we enable the DMA support? */
if (is_imx6q_uart(sport) && !uart_console(port)
&& !sport->dma_is_inited)
imx_uart_dma_init(sport);
} else {
termios->c_cflag &= ~CRTSCTS;
}
@ -1432,6 +1429,8 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
imx_enable_ms(&sport->port);
if (sport->dma_is_inited && !sport->dma_is_enabled)
imx_enable_dma(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
}