imx8mm not switching from earlycon to "real" console

[dpog]

After solving my problem with the earlycon, I now am stuck at the next point. Earlycon runs at 0x30880000 (Uart 3), and in the bootargs I set console=ttymxc2,115200. I also tried using ttymxc1 (Uart 2 is accessable via Jumpers on the custom board), still no Log.

The Kernel Log is Stuck at the 8250/16550 driver, I believe the board tries to switch to the real console at this point.

Any help would be appreciated!

[dpog]

I figured out that the jumpers on the Uart2 / ttymxc1 were connected wrong. When I set console=ttymxc1 i get an output, but still nothing on ttymxc2

[Zhiming_Liu]

Let me try to summary:

1.You need get log from ttymxc2,right?

2.Have you got the log you want from the ttymxc1?

[dpog]

1. Yes
2. If I set console=ttymxc1, yes.
In the meantime i figured out that the pin configuration in the device tree was wrong, the used pins were configured as Uart1 CTS & RTS.

pinctrl_uart1: uart1grp {
fsl,pins = <
MX8MM_IOMUXC_UART1_RXD_UART1_DCE_RX 0x140
MX8MM_IOMUXC_UART1_TXD_UART1_DCE_TX 0x140
MX8MM_IOMUXC_UART3_RXD_UART1_DCE_CTS_B 0x140
MX8MM_IOMUXC_UART3_TXD_UART1_DCE_RTS_B 0x140
MX8MM_IOMUXC_SD1_DATA4_GPIO2_IO6 0x19
>;
};
pinctrl_uart3: uart3grp {
fsl,pins = <
MX8MM_IOMUXC_ECSPI1_SCLK_UART3_DCE_RX 0x140
MX8MM_IOMUXC_ECSPI1_MOSI_UART3_DCE_TX 0x140
MX8MM_IOMUXC_ECSPI1_SS0_UART3_DCE_RTS_B 0x140
MX8MM_IOMUXC_ECSPI1_MISO_UART3_DCE_CTS_B 0x140
>;
};

When I now change the uart3-configuration, I get an output as wanted, but it highly irritates me that I then can't send anything, even in the uboot, where the pin config was done previously and working fine. The change in the Kernel-DT should have no impact on the uboot behaviour, as the Kernel-DT isn't even loaded at that stage

[dpog · Accepted solution]

The Problem has resolved itself, the Pin Configuration did the trick, the "send"-error came from my putty-terminal, after a restart it's now working fine.

[Zhiming_Liu]

After solving my problem with the earlycon, I now am stuck at the next point. Earlycon runs at 0x30880000 (Uart 3)

-->How do you enable the earlycon?

[dpog]

The Earlycon is enabled within the bootargs by setting earlycon=ec_imx6q,0x30880000,115200

[dpog]

Additional Information: if I set console=tty2 (or something else, for that matter), the bootconsole is disabled nearly instantly
...
[ 0.000000] random: get_random_bytes called from start_kernel+0x2b8/0x43c with crng_init=0
[ 0.000000] arch_timer: cp15 timer(s) running at 8.00MHz (phys).
[ 0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x1d854df40, max_idle_ns: 440795202120 ns
[ 0.000003] sched_clock: 56 bits at 8MHz, resolution 125ns, wraps every 2199023255500ns
[ 0.008450] Console: colour dummy device 80x25
[ 0.012519] printk: console [tty2] enabled
[ 0.016629] printk: bootconsole [ec_imx6q0] disabled