Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 907eda32 authored by David Jander's avatar David Jander Committed by Greg Kroah-Hartman
Browse files

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



This reverts commit 068500e0.

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: default avatarDavid Jander <david@protonic.nl>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dec273ec

drivers/tty/serial/imx.c

+7 −8
Original line number Diff line number Diff line
@@ -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);

}