uart_callback_set returns -ENOSYS

[fgeldenh]

I have two projects using different boards.

First one (uses attached board = btLTE_nrf52840) works fine. The application are similar in that both make use of the UARTE driver.

The second one (uses attached board = w5500_nrf52840) uses the W5500 Ethernet driver. This application works fine except that in the case of the second board, uart_callback_set() returns error -ENOSYS. I have seen other cases reported for the same issue, but I have not been able to determine why this is the case.

I must be something to do with the settings or the board.

I would appreciate any assistance.

I include the im7851.code.zipplementation for both boards, the config settings for working and none working applicayion as well as the

common uart code.

[Jørgen Holmefjord]

Hi,

The main difference that I can see is that "CONFIG_SERIAL=y" is set in the board defconfig file for the working board, but not for the failing board. I see that this is set in both prj.conf files, so as long as these are used correctly when building, this should not be a problem.

Do you see any warnings/errors during building?

Can you provide the build/zephyr/zephyr.dts and build/zephyr/.config files from both builds?

Best regards,
Jørgen

[fgeldenh]

Jorgen - I tried adding "CONFIG_SERIAL=y" to the defconfig and still get the issue.

I am attaching a log of the build output as well as the files requested for each board.

[fgeldenh]

requested files.zip

[fgeldenh]

I have created a bare bones project that can run on any ARM hardware. The issue still persists.

nrf_testcode.zip

[Jørgen Holmefjord]

Hi,

The problem is likely that the uart0 instance is used by the NET_SHELL that you have enabled in your prj.conf file. In /build/zephyr/zephyr.dts, we can see:

/ {
	chosen {
		zephyr,shell-uart = &uart0;
	};
};

You can either disable NET_SHELL in your prj.conf:

CONFIG_NET_SHELL=n

Or assign it to another uart instance in your board overlay:

/ {
	chosen {
		zephyr,shell-uart = &uart1;
	};
};

Both these alternatives resolved the error in your test application.

Best regards,
Jørgen