imx6: disable dma on uart
[openwrt/openwrt.git] / target / linux / imx6 / patches-4.14 / 210-disable-uart-dma.patch
1 Based on following upstream patch by Tim Harvey (Gateworks):
2
3 https://github.com/Gateworks/openwrt/commit/80a01b6582f94c4547f39d3a25e0a1e9b6eb9877
4
5 TX complete DMA messages are getting missed.
6 This is also currently an issue in mainline.
7 For now we will disable DMA in serial/imx.c.
8
9 This resolves an issue encountered with RS485 transmit.
10
11 --- a/drivers/tty/serial/imx.c
12 +++ b/drivers/tty/serial/imx.c
13 @@ -1268,10 +1268,6 @@ static int imx_startup(struct uart_port
14
15 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
16
17 - /* Can we enable the DMA support? */
18 - if (!uart_console(port) && !sport->dma_is_inited)
19 - imx_uart_dma_init(sport);
20 -
21 spin_lock_irqsave(&sport->port.lock, flags);
22 /* Reset fifo's and state machines */
23 i = 100;