On Ventana boards the Gateworks System Controller is the only device on I2C1 (/dev/i2c-0) and it can NAK transfers if it is busy in an ADC loop. Because this is a multi-function device with several slave addresses it is best to add retries at the controller level instead of within each slave driver. This adds a patch that adds 3 retries for i2c transactions only for Ventana boards and only for I2C1
Signed-off-by: Tim Harvey <[email protected]> Signed-off-by: Pushpal Sidhu <[email protected]> --- ...x-add-retries-for-NAK-s-on-ventana-boards.patch | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 target/linux/imx6/patches-4.3/207-i2c-imx-add-retries-for-NAK-s-on-ventana-boards.patch diff --git a/target/linux/imx6/patches-4.3/207-i2c-imx-add-retries-for-NAK-s-on-ventana-boards.patch b/target/linux/imx6/patches-4.3/207-i2c-imx-add-retries-for-NAK-s-on-ventana-boards.patch new file mode 100644 index 0000000..bfb5707 --- /dev/null +++ b/target/linux/imx6/patches-4.3/207-i2c-imx-add-retries-for-NAK-s-on-ventana-boards.patch @@ -0,0 +1,24 @@ +Index: linux-4.3/drivers/i2c/busses/i2c-imx.c +=================================================================== +--- linux-4.3.orig/drivers/i2c/busses/i2c-imx.c 2015-11-01 16:05:25.000000000 -0800 ++++ linux-4.3/drivers/i2c/busses/i2c-imx.c 2015-12-18 10:39:44.971158318 -0800 +@@ -461,6 +461,8 @@ + { + if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) { + dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__); ++ if (i2c_imx->adapter.retries) ++ return -EAGAIN; + return -EIO; /* No ACK */ + } + +@@ -1010,6 +1012,10 @@ + i2c_imx->adapter.nr = pdev->id; + i2c_imx->adapter.dev.of_node = pdev->dev.of_node; + i2c_imx->base = base; ++ if (of_machine_is_compatible("gw,ventana") && phy_addr == 0x021a0000) { ++ dev_info(&pdev->dev, "Adding retries for Ventana GSC\n"); ++ i2c_imx->adapter.retries = 3; ++ } + + /* Get I2C clock */ + i2c_imx->clk = devm_clk_get(&pdev->dev, NULL); -- 2.6.4 _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
