lib: lte_link_control: Fix missing eDRX events with non-NTN firmware

The library tried to always configure eDRX also for NTN NB-IoT. This
causes an error with non-NTN modem firmware, which also causes the
+CEDRXS notification subscription to be removed. To mitigate this,
the order in which eDRX is configured for access technologies has
been changed. This commit also adds checking of the modem firmware
type, so that configuring eDRX for NTN NB-IoT is skipped when
non-NTN firmware is detected.

Signed-off-by: Tommi Kangas <[email protected]>

Author: tokangas

lib/lte_link_control/common/helpers.c

@@ -7,10 +7,40 @@
 #include <stdlib.h>
 #include <zephyr/logging/log.h>
 
+#include <modem/nrf_modem_lib.h>
+#include <nrf_modem_at.h>
+
 #include <common/helpers.h>
 
 LOG_MODULE_DECLARE(lte_lc, CONFIG_LTE_LINK_CONTROL_LOG_LEVEL);
 
+static enum mfw_type mfw_type = MFW_TYPE_UNKNOWN;
+
+void mfw_type_init(void)
+{
+	int err;
+	char buf[64];
+
+	err = nrf_modem_at_cmd(buf, sizeof(buf), "AT+CGMR");
+	if (err) {
+		LOG_ERR("Failed to get modem firmware type, error: %d", err);
+		return;
+	}
+
+	if (strstr(buf, "nrf9160_") != NULL) {
+		mfw_type = MFW_TYPE_NRF9160;
+	} else if (strstr(buf, "nrf91x1_") != NULL) {
+		mfw_type = MFW_TYPE_NRF91X1;
+	} else if (strstr(buf, "nrf9151-ntn_") != NULL) {
+		mfw_type = MFW_TYPE_NRF9151_NTN;
+	}
+}
+
+enum mfw_type mfw_type_get(void)
+{
+	return mfw_type;
+}
+
 int string_to_int(const char *str_buf, int base, int *output)
 {
 	int temp;

lib/lte_link_control/common/work_q.c

@@ -15,7 +15,7 @@ static struct k_work_q work_q;
 void work_q_start(void)
 {
 	struct k_work_queue_config cfg = {
-		.name = "work_q",
+		.name = "lte_lc_work_q",
 	};
 
 	k_work_queue_start(&work_q, work_q_stack, K_THREAD_STACK_SIZEOF(work_q_stack),

lib/lte_link_control/include/common/helpers.h

@@ -17,6 +17,19 @@
 extern "C" {
 #endif
 
+enum mfw_type {
+	MFW_TYPE_UNKNOWN,
+	MFW_TYPE_NRF9160,
+	MFW_TYPE_NRF91X1,
+	MFW_TYPE_NRF9151_NTN
+};
+
+/* Initialize the modem firmware type (read it from the modem). */
+void mfw_type_init(void);
+
+/* Get the modem firmware type. */
+enum mfw_type mfw_type_get(void);
+
 /* Converts integer as string to integer type. */
 int string_to_int(const char *str_buf, int base, int *output);
 

lib/lte_link_control/lte_lc_modem_hooks.c

@@ -11,6 +11,7 @@
 
 #include "modules/rai.h"
 #include "modules/dns.h"
+#include "common/helpers.h"
 
 LOG_MODULE_DECLARE(lte_lc, CONFIG_LTE_LINK_CONTROL_LOG_LEVEL);
 
@@ -30,6 +31,8 @@ static void on_modem_init(int err, void *ctx)
 		return;
 	}
 
+	mfw_type_init();
+
 	if (!IS_ENABLED(CONFIG_LTE_NETWORK_MODE_DEFAULT)) {
 		err = lte_lc_system_mode_set(lte_lc_sys_mode, lte_lc_sys_mode_pref);
 		if (err) {

lib/lte_link_control/modules/edrx.c

@@ -16,6 +16,7 @@
 #include <nrf_modem_at.h>
 
 #include "common/work_q.h"
+#include "common/helpers.h"
 #include "common/event_handler_list.h"
 #include "modules/edrx.h"
 
@@ -96,10 +97,21 @@ static void lte_lc_edrx_values_store(enum lte_lc_lte_mode mode, char *edrx_value
 static void edrx_ptw_send_work_fn(struct k_work *work_item)
 {
 	int err;
-	int actt[] = {AT_CEDRXS_ACTT_WB, AT_CEDRXS_ACTT_NB, AT_CEDRXS_ACTT_NTN_NB};
+	int actt[3];
+	uint8_t actt_count = 0;
+	enum mfw_type mfw_type = mfw_type_get();
 
-	/* Apply the configurations for LTE-M, NB-IoT and NTN NB-IoT. */
-	for (size_t i = 0; i < ARRAY_SIZE(actt); i++) {
+	if (mfw_type == MFW_TYPE_NRF9151_NTN || mfw_type == MFW_TYPE_UNKNOWN) {
+		actt[actt_count] = AT_CEDRXS_ACTT_NTN_NB;
+		actt_count++;
+	}
+	actt[actt_count] = AT_CEDRXS_ACTT_WB;
+	actt_count++;
+	actt[actt_count] = AT_CEDRXS_ACTT_NB;
+	actt_count++;
+
+	/* Apply the configurations. */
+	for (size_t i = 0; i < actt_count; i++) {
 		char *requested_ptw_value =
 			(actt[i] == AT_CEDRXS_ACTT_WB) ? requested_ptw_value_ltem :
 			(actt[i] == AT_CEDRXS_ACTT_NB) ? requested_ptw_value_nbiot :
@@ -114,10 +126,7 @@ static void edrx_ptw_send_work_fn(struct k_work *work_item)
 
 			err = nrf_modem_at_printf("AT%%XPTW=%d,\"%s\"", actt[i],
 						  requested_ptw_value);
-			/* Setting PTW for NTN NB-IoT causes an error with non-NTN firmwares, so
-			 * silently ignore errors for it.
-			 */
-			if (err && actt[i] != AT_CEDRXS_ACTT_NTN_NB) {
+			if (err) {
 				LOG_ERR("Failed to request PTW, reported error: %d", err);
 			}
 		}
@@ -413,7 +422,22 @@ int edrx_ptw_set(enum lte_lc_lte_mode mode, const char *ptw)
 int edrx_request(bool enable)
 {
 	int err = 0;
-	int actt[] = {AT_CEDRXS_ACTT_WB, AT_CEDRXS_ACTT_NB, AT_CEDRXS_ACTT_NTN_NB};
+	int actt[3];
+	uint8_t actt_count = 0;
+	enum mfw_type mfw_type = mfw_type_get();
+
+	/* Try to configure for NTN NB-IoT first, because a failing +CEDRXS command removes
+	 * the +CEDRXS notification subscription. eDRX is configured for NTN NB-IoT only when
+	 * when modem firmware has NTN support or when firmware type can not be determined.
+	 */
+	if (mfw_type == MFW_TYPE_NRF9151_NTN || mfw_type == MFW_TYPE_UNKNOWN) {
+		actt[actt_count] = AT_CEDRXS_ACTT_NTN_NB;
+		actt_count++;
+	}
+	actt[actt_count] = AT_CEDRXS_ACTT_WB;
+	actt_count++;
+	actt[actt_count] = AT_CEDRXS_ACTT_NB;
+	actt_count++;
 
 	LOG_DBG("enable=%d, "
 		"requested_edrx_value_ltem=%s, edrx_value_ltem=%s, "
@@ -444,8 +468,8 @@ int edrx_request(bool enable)
 		return 0;
 	}
 
-	/* Apply the configurations for LTE-M, NB-IoT and NTN NB-IoT. */
-	for (size_t i = 0; i < ARRAY_SIZE(actt); i++) {
+	/* Apply the configurations. */
+	for (size_t i = 0; i < actt_count; i++) {
 		char *requested_edrx_value =
 			(actt[i] == AT_CEDRXS_ACTT_WB) ? requested_edrx_value_ltem :
 			(actt[i] == AT_CEDRXS_ACTT_NB) ? requested_edrx_value_nbiot :
@@ -467,10 +491,7 @@ int edrx_request(bool enable)
 			err = nrf_modem_at_printf("AT+CEDRXS=2,%d", actt[i]);
 		}
 
-		/* Setting eDRX for NTN NB-IoT causes an error with non-NTN firmwares, so
-		 * silently ignore errors for it.
-		 */
-		if (err && actt[i] != AT_CEDRXS_ACTT_NTN_NB) {
+		if (err) {
 			LOG_ERR("Failed to enable eDRX, reported error: %d", err);
 			return -EFAULT;
 		}

samples/cellular/modem_shell/src/link/link.c

@@ -432,7 +432,7 @@ void link_ind_handler(const struct lte_lc_evt *const evt)
 
 		len = snprintf(
 			log_buf, sizeof(log_buf),
-			"eDRX parameter update: eDRX: %f, PTW: %f",
+			"eDRX parameter update: eDRX: %.2f, PTW: %.2f",
 			(double)evt->edrx_cfg.edrx, (double)evt->edrx_cfg.ptw);
 		if (len > 0) {
 			mosh_print("%s", log_buf);