ESP32-C6 CONFIG_SOC_UART_NUM wrongly set to 3 (IDFGH-10775)

[petergjoel]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

IDF version.

28167ea

Operating System used.

Linux

How did you build your project?

Command line with idf.py

If you are using Windows, please specify command line type.

None

What is the expected behavior?

I expect CONFIG_SOC_UART_NUM to be set to 2 which is consistent with the documentation.

What is the actual behavior?

CONFIG_SOC_UART_NUM is set to 3, causing issues with compilation of e.g. Arduino libraries.

Steps to reproduce.

1. Set up a project for ESP-C6
2. Observe the sdkconfig file
3. (extra) try to include and compile an example with https://github.com/espressif/arduino-esp32/blob/esp-idf-v5.1-libs

Build or installation Logs.

No response

More Information.

No response

[igrr]

This is probably something that has to updated on arduino-esp32 side. SOC_UART_NUM still means "number of UART peripherals in the chip", but one of these UARTs on ESP32-C6 is the LP_UART peripheral. From IDF perspective, LP_UART can also be used with the UART driver (921713f).

To find the number of non-LP UARTs there is another option, SOC_UART_HP_NUM.

[petergjoel]

@igrr, makes sense. I will forward the issue to the arduino-esp32.