From: Koen Vandeputte Date: Mon, 5 Nov 2018 16:41:00 +0000 (+0100) Subject: imx6: fix DMA transaction errors X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=44084d89f2b0f60ba6d0d480ebf4d944c1ebe57d;p=openwrt%2Fstaging%2Fxback.git imx6: fix DMA transaction errors Following errors were seen in the past on imx6 when using serial: [ 22.617622] imx-uart 2020000.serial: DMA transaction error. [ 22.623228] imx-uart 2020000.serial: DMA transaction error. [ 22.628826] imx-uart 2020000.serial: DMA transaction error. [ 22.648951] imx-uart 2020000.serial: DMA transaction error. [ 22.654558] imx-uart 2020000.serial: DMA transaction error. [ 22.660156] imx-uart 2020000.serial: DMA transaction error. Which is the reason why DMA for the serial ports got disabled in commits: efb362cd93b0 ("imx6: disable dma on uart") 3b4241071dd4 ("imx6: disable UART dma") As indicated on mailinglist discussion, the cause seems to be the usage of very old SDMA firmware which is present in the soc: [ 0.624302] imx-sdma 20ec000.sdma: Direct firmware load for imx/sdma/sdma-imx6q.bin failed with error -2 [ 0.624318] imx-sdma 20ec000.sdma: Falling back to user helper [ 64.531607] imx-sdma 20ec000.sdma: external firmware not found, using ROM firmware This patch adds the new firmware binary. (2196 bytes) It is required to embed the binary into the kernel image, as it gets loaded very early in the boot process where the rootfs is not available yet: [ 0.622966] imx-sdma 20ec000.sdma: loaded firmware 3.3 Extended testing shows that the DMA errors are not seen anymore when using this newer firmware version. Signed-off-by: Koen Vandeputte --- diff --git a/target/linux/imx6/config-4.14 b/target/linux/imx6/config-4.14 index 7829b4b507..52a98a0ba8 100644 --- a/target/linux/imx6/config-4.14 +++ b/target/linux/imx6/config-4.14 @@ -178,6 +178,8 @@ CONFIG_EXT4_FS_ENCRYPTION=y CONFIG_EXT4_FS_POSIX_ACL=y CONFIG_EXT4_FS_SECURITY=y CONFIG_EXTCON=y +CONFIG_EXTRA_FIRMWARE="imx/sdma/sdma-imx6q.bin" +CONFIG_EXTRA_FIRMWARE_DIR="firmware" CONFIG_FEC=y CONFIG_FIXED_PHY=y CONFIG_FIX_EARLYCON_MEM=y diff --git a/target/linux/imx6/files/firmware/imx/sdma/sdma-imx6q.bin b/target/linux/imx6/files/firmware/imx/sdma/sdma-imx6q.bin new file mode 100644 index 0000000000..f0b5252a6f Binary files /dev/null and b/target/linux/imx6/files/firmware/imx/sdma/sdma-imx6q.bin differ 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 deleted file mode 100644 index 6abbb93301..0000000000 --- a/target/linux/imx6/patches-4.14/210-disable-uart-dma.patch +++ /dev/null @@ -1,23 +0,0 @@ -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;