Error while blending two Nordic samples – the WiFi Provisioning sample and the Memfault sample

Question

Hello Nordic, 
 I hope this message finds you well. I wanted to reach out to you all for some guidance regarding a challenge I'm facing with my nRF7002DK board. I'm relatively new to Zephyr, and I think that's where I'm hitting a snag. 
 I've been working on merging two Nordic samples - the WiFi Provisioning sample and the Memfault sample . Each works fine on its own, but I'm encountering issues when I try to combine them into a single project. Specifically, I'm attempting to replace the WiFi static credentials with Bluetooth for provisioning, but this leads to the provisioning service failing to connect to the WiFi network. 
 You can find my project here: Provisioning-memfault on GitHub . I would appreciate it if you could try to run it and provide any insights, advice, or pointers you can share. 
 What I found was that I was able to retrieve the SSID of the Wi-Fi and the passkey. I ended up in this file: 
cs\v2.5.99-dev1
rf\subsys\bluetooth\services\wifi_prov\wifi_prov_handler.c. 
 The error happens inside this function: static void prov_set_config_handler(Request *req, Response *rsp). This particular code blob is where the error occurs. In our case, we end up in error path number 4. I don't understand why the network management layer suddenly fails to connect when we integrate memfault. I can't pinpoint what has changed in the configuration. 
 
 rc = net_mgmt(NET_REQUEST_WIFI_CONNECT, iface, &cnx_params,
 sizeof(struct wifi_connect_req_params));
	/* Invalid argument error. */
	if (rc == -EINVAL) {
 rsp->has_status = true;
 rsp->status = Status_INVALID_ARGUMENT;
 LOG_ERR(" 3 ");
 return;
	}
	/* Other error. */
	if (rc != 0) {
 rsp->has_status = true;
 rsp->status = Status_INTERNAL_ERROR;
 LOG_ERR(" 4 ");
 return;
	}

Håkon Alseth · Accepted Answer

Hi, 
 
 My apologies, this is due to the CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE in this specific configuration. It needs to be higher. I have asked R&D for what the min. value should be here, and requested that this would be added to our documentation. I got your current code, with all overlay configs, running by setting CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE to '37000' bytes. 
 My former suggestions on for instance CONFIG_NET_OFFLOAD=y and disabling NET_CONNECTION_MANAGER is not correct. It was a incorrect amount of RAM allocated to the libc heap that was the root-cause, and changing the local configuration (ie. reducing memory) allowed libc heap to use more RAM, as the default configuration is to use all available RAM. 
 Actif said: 
 Added CONFIG_NET_OFFLOAD=y as per diff file. 
 As the original issue is rooted in memory allocation issues, you can revert this. I tried several settings based on other samples, and offloading the net stack in zephyr is not required for your use-case. 
 Actif said: Current Status: Lines 152-157 have been uncommented. But what is the guidance from your side? 
 Keep this as original, ie. call conn_mgr_* API calls as needed by the module. 
 
 Kind regards, 
 Håkon

Error while blending two Nordic samples – the WiFi Provisioning sample and the Memfault sample

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