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Diffstat (limited to 'target/linux/imx6/patches-4.14/210-disable-uart-dma.patch')
-rw-r--r--target/linux/imx6/patches-4.14/210-disable-uart-dma.patch23
1 files changed, 23 insertions, 0 deletions
diff --git a/target/linux/imx6/patches-4.14/210-disable-uart-dma.patch b/target/linux/imx6/patches-4.14/210-disable-uart-dma.patch
new file mode 100644
index 0000000000..6abbb93301
--- /dev/null
+++ b/target/linux/imx6/patches-4.14/210-disable-uart-dma.patch
@@ -0,0 +1,23 @@
+Based on following upstream patch by Tim Harvey (Gateworks):
+
+https://github.com/Gateworks/openwrt/commit/80a01b6582f94c4547f39d3a25e0a1e9b6eb9877
+
+TX complete DMA messages are getting missed.
+This is also currently an issue in mainline.
+For now we will disable DMA in serial/imx.c.
+
+This resolves an issue encountered with RS485 transmit.
+
+--- a/drivers/tty/serial/imx.c
++++ b/drivers/tty/serial/imx.c
+@@ -1268,10 +1268,6 @@ static int imx_startup(struct uart_port
+
+ writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
+
+- /* Can we enable the DMA support? */
+- if (!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;