Handling time out for lte_lc_connect_async

Question

Hi, I want to set and catch a timeout event when connecting async to LTE, but I fail to see how this would work. 
 For lte_lc_connect this is clear:

Set CONFIG_LTE_NETWORK_TIMEOUT (default 600) 
 
 Check the return code ( ETIMEDOUT for time out) 
 
 But for the async variant lte_lc_connect_async , the CONFIG_LTE_NETWORK_TIMEOUT doesn't seem to be used in lte_lc.c. 
 in lte_connect(false):
 ...
	err = lte_lc_func_mode_set(LTE_LC_FUNC_MODE_NORMAL);
	if (err || !blocking) {
 goto exit; // Exit when non-blocking and never using the timeout value
	}

	err = k_sem_take(&link, K_SECONDS(CONFIG_LTE_NETWORK_TIMEOUT));
	if (err == -EAGAIN) {
 LOG_INF("Network connection attempt timed out");
 ... 
 
 Is it possible to LTE_NETWORK_TIMEOUT for lte_lc_connect_async? 
 
 If so, how?

If not, what would be the best solution to avoid the device to search forever? 
 
 We started from asset tracker v2 app which has a dedicated modem_module thread, so we could switch to a sync blocking call for the network connection? 
 Or implement or own timeout timer on top of the existing code

Thanks in advance!

Mariano Goluboff · Accepted Answer

You could setup your own thread and use the blocking call, but another way with less overhead is to submit a delayable work item to the system workqueue: 
 https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/kernel/services/threads/workqueue.html#delayable-work 
 
 Then when that work item is called, you can check if the modem is connected and take appropriate action if it's not.

Handling time out for lte_lc_connect_async

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