RMII with imx6sx doesn't work on kernel v4.9

[tparka]

Hello,
We have custom modules based on imx6sx.
Our firmware based on Yocto Project Version 2.5 (sumo) - everythig works fine of it.
Last time we updated Yocto to versio 2.7 (warrior), but Ethernet doesn't work on it.
So kernel was updated from 4.1 to 4.9 (we tested also 4.19).
We use RMII mode (50Mhz + SION bit is set).
So when SION bit is set (according to description in imx6sx-pinfunc.h) the kernel (v4.9) hang on Network configuration.

What could possibly be wrong?

Here you have part of our dts file:
#include "imx6sx.dtsi"
...
&fec1 {
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_enet1>;
    phy-reset-gpios = <&gpio2 0 0>;
    phy-mode = "rmii";
    status = "okay";
};
...
pinctrl_enet1: enet1grp {
            fsl,pins = <
                MX6SX_PAD_ENET1_MDIO__ENET1_MDIO    0x1b0b1
                MX6SX_PAD_ENET1_MDC__ENET1_MDC        0x1b0b1
                MX6SX_PAD_RGMII1_RX_CTL__ENET1_RX_EN     0x1b0b1
                MX6SX_PAD_ENET1_TX_CLK__ENET1_REF_CLK1  0x0051
                MX6SX_PAD_RGMII1_TD0__ENET1_TX_DATA_0    0x1b0b1
                MX6SX_PAD_RGMII1_TD1__ENET1_TX_DATA_1    0x1b0b1
                MX6SX_PAD_RGMII1_TX_CTL__ENET1_TX_EN    0x1b0b1
                MX6SX_PAD_RGMII1_RD0__ENET1_RX_DATA_0    0x1b0b1
                MX6SX_PAD_RGMII1_RD1__ENET1_RX_DATA_1    0x1b0b1
                MX6SX_PAD_ENET1_COL__GPIO2_IO_0        0x10b0
            >;
        };
        
        
Here you have part of our patches:
Index: kernel-source/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
===================================================================
--- kernel-source.orig/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
+++ kernel-source/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
@@ -424,9 +424,9 @@
 #define IMX6SX_GPR1_VADC_SW_RST_MASK            (0x1 << 19)
 #define IMX6SX_GPR1_VADC_SW_RST_RESET            (0x1 << 19)
 #define IMX6SX_GPR1_VADC_SW_RST_RELEASE        (0x0 << 19)
-#define IMX6SX_GPR1_FEC_CLOCK_MUX_SEL_MASK        (0x3 << 13)
-#define IMX6SX_GPR1_FEC_CLOCK_PAD_DIR_MASK        (0x3 << 17)
-#define IMX6SX_GPR1_FEC_CLOCK_MUX_SEL_EXT        (0x3 << 13)
+#define IMX6SX_GPR1_FEC_CLOCK_MUX_SEL_MASK        (0x1 << 13)
+#define IMX6SX_GPR1_FEC_CLOCK_PAD_DIR_MASK        (0x1 << 17)
+#define IMX6SX_GPR1_FEC_CLOCK_MUX_SEL_EXT        (0x1 << 13)
 
 #define IMX6SX_GPR4_FEC_ENET1_STOP_REQ            (0x1 << 3)
 #define IMX6SX_GPR4_FEC_ENET2_STOP_REQ            (0x1 << 4)
Index: kernel-source/arch/arm/mach-imx/mach-imx6sx.c
===================================================================
--- kernel-source.orig/arch/arm/mach-imx/mach-imx6sx.c
+++ kernel-source/arch/arm/mach-imx/mach-imx6sx.c
@@ -84,7 +84,7 @@ static void __init imx6sx_enet_clk_sel(v
         regmap_update_bits(gpr, IOMUXC_GPR1,
                    IMX6SX_GPR1_FEC_CLOCK_MUX_SEL_MASK, 0);
         regmap_update_bits(gpr, IOMUXC_GPR1,
-                   IMX6SX_GPR1_FEC_CLOCK_PAD_DIR_MASK, 0);
+                   IMX6SX_GPR1_FEC_CLOCK_PAD_DIR_MASK, IMX6SX_GPR1_FEC_CLOCK_PAD_DIR_MASK);
     } else {
         pr_err("failed to find fsl,imx6sx-iomux-gpr regmap\n");
     }
Index: kernel-source/arch/arm/boot/dts/imx6sx-pinfunc.h
===================================================================
--- kernel-source.orig/arch/arm/boot/dts/imx6sx-pinfunc.h
+++ kernel-source/arch/arm/boot/dts/imx6sx-pinfunc.h
@@ -330,7 +330,7 @@
  * also connected to that pin and using respective function as input (e.g.
  * UART1's DTR handling on MX6SX_PAD_ENET1_TX_CLK__UART1_DTR_B).
  */
-#define MX6SX_PAD_ENET1_TX_CLK__ENET1_REF_CLK1                    0x0090 0x03D8 0x0760 0x1 0x1
+#define MX6SX_PAD_ENET1_TX_CLK__ENET1_REF_CLK1                    0x0090 0x03D8 0x0760 0x11 0x1
 #define MX6SX_PAD_ENET1_TX_CLK__AUDMUX_AUD4_RXD                   0x0090 0x03D8 0x0644 0x2 0x1
 #define MX6SX_PAD_ENET1_TX_CLK__UART1_DTR_B                       0x0090 0x03D8 0x0000 0x3 0x0
 #define MX6SX_PAD_ENET1_TX_CLK__SPDIF_SR_CLK                      0x0090 0x03D8 0x0000 0x4 0x0
 Index: kernel-source/arch/arm/mach-imx/clk-imx6sx.c
===================================================================
--- kernel-source.orig/drivers/clk/imx/imx/clk-imx6sx.c
+++ kernel-source/drivers/clk/imx/clk-imx6sx.c
@@ -617,8 +617,8 @@ static void __init imx6sx_clocks_init(st
     imx_clk_set_parent(clks[IMX6SX_CLK_ENET_PRE_SEL], clks[IMX6SX_CLK_PLL2_PFD2]);
     imx_clk_set_parent(clks[IMX6SX_CLK_ENET_SEL], clks[IMX6SX_CLK_ENET_PODF]);
     imx_clk_set_rate(clks[IMX6SX_CLK_ENET_PODF], 200000000);
-    imx_clk_set_rate(clks[IMX6SX_CLK_ENET_REF], 125000000);
-    imx_clk_set_rate(clks[IMX6SX_CLK_ENET2_REF], 125000000);
+        imx_clk_set_rate(clks[IMX6SX_CLK_ENET_REF], 50000000);
+    imx_clk_set_rate(clks[IMX6SX_CLK_ENET2_REF], 50000000);
 
     /* Audio clocks */
     imx_clk_set_rate(clks[IMX6SX_CLK_PLL4_AUDIO_DIV], 393216000);

[igorpadykov]

Hi Tomasz

nxp does not support yocto version 2.7 (warrior) yet according to

oficial linux documentation (Release Notes sec.2.1 New features) from link

i.MX Software | NXP 

4.19 is based on version 2.6 Thud: Documentation.

One can try with nxp linux from source.codeaurora.org/external/imx repository

linux-imx - i.MX Linux kernel 

Best regards
igor
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[tparka]

Thanks for your quick response.

Sorry, I think I wasn't too precise with my description,

we already tested several options.

Our firmware is based on Yocto 2.5, but we didn't update recipes for long time,
so until now our firmware used meta-freescale/recipes-kernel/linux/linux-fslc-imx_4.1-2.0.x.bb for kernel

Today I updated meta-freescale to the newest commit on Sumo branch

so now we have:

linux-fslc-imx_4.9-1.0.x.bb

Unfortunately after rebuild firmware with the new kernel (4.9) the result is the same as for Thud and Warrior - kernel hangs on Configuring network interfaces

here is the end of the kernel log:

mount sdcard

FAT-fs (mmcblk3p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.

INIT: Entering runlevel: 5

Configuring network interfaces...

the only things I did after the meta-freescale update were:

* Prepare defconfig for new kernel

* Adjust our patches to meet changes in sources (patches that I described before)

Any idea why it works fine on 4.1 but not on 4.9?

[igorpadykov]

"linux-fslc-imx" is community version of linux not supported by nxp, one can check

difference between Yocto Community BSP and Freescale BSP Release 

Please try official nxp linux from source.codeaurora.org/external/imx repository,

follow documentation from i.MX Software | NXP 

Best regards
igor

[tparka]

One more thing
we noticed that the clock is not generated

[igorpadykov]

one can start to investigate it in uboot setup_fec() :

mx6sxsabresd.c\mx6sxsabresd\freescale\board - uboot-imx - i.MX U-Boot 

[tparka]

We tried official nxp linux (v. 4.9.88),
unfortunately with the same result.