Rock Pi S with 3 UART (Hardware v1.1)

Hello,

i have all 3 UART enabled and only UART 0 and UART 1 works. UART 2 isn’t working at all. Is there any known issue? I currently need all 3 of them.

Thanks & Regards.

Update:

both pins (rx/tx) work in GPIO mode as expected but as UART2 this pins doesn’t work.

It seems the Kernel DTS is buggy. This ugly patch will fix it: https://pastebin.com/a0xw6CMX
But it will disable wireless and uart0 rts/cts functions but it works for me because i have a no wifi board.
Would be nice if you can fix it in the future.

The next problem is u-boot, it will stop the autoboot if there is any data on UART0 …

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uart2 (/dev/ttyS2) is still buggy on Hardware V1.2 without BT Wifi on debian buster (2020-03-16) updated (26.05.2020) with versions
rockchip-overlay 2.6
kernel 4.4.143-47-rockchip-g495ff574976c

rk3308-uart2
this enables the kernel console on uart2, but it should not

rk3308-console-on-uart2
this enables the kernel console on uart2, but with unreadable output

Hi ,I suggest that you use this image https://dl.radxa.com/rockpis/images/debian/rockpis_debian_buster_minimal_arm64_20200528_1227-gpt.img.gz.

To use 3 UARTs, you can view the " Common Hardware Interfaces" part of https://wiki.radxa.com/RockpiS/Debian.

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Hi, I got the debian buster (2020-03-16) image working. I will also try the newer image, thanks.
Regarding the debian buster (2020-03-16) image:
The uart2 is configured serial-console at default in boot.cmd. To disable it, one has to unset console in uEnv.txt. Example:

In uEnv.txt
console=

This disables the serial console on uart2, which enabled by default in debian buster (2020-03-16). Interestingly choosing rk3308-console-on-uart2 with default settings gives double output of console to uart2, which results in unreadable gibberish.

The new debian image is also working, and easier to configure, thank you.