uqmi: fix network registration loop

With some debug in qmi.sh using following patch, some errors are visible
in the registration step
@@ -29,6 +29,7 @@ proto_qmi_init_config() {
 }

 proto_qmi_setup() {
+       set -x
        local interface="$1"
        local dataformat connstat plmn_mode mcc mnc
        local device apn auth username password pincode delay modes pdptype
@@ -224,6 +225,8 @@ proto_qmi_setup() {
                fi
        done

+       registration=$(uqmi -s -d "$device" --get-serving-system)
+
        [ -n "$modes" ] && uqmi -s -d "$device" --set-network-modes "$modes" > /dev/null 2>&1

        echo "Starting network $interface"

During the boot of the system, modem could not start automatically its
network registration.
netifd: wan (9235): + echo 'Waiting for network registration'
netifd: wan (9235): Waiting for network registration
netifd: wan (9235): + local 'registration_timeout=0'
netifd: wan (9235): + uqmi -s -d /dev/cdc-wdm1 --get-serving-system
netifd: wan (9235): + grep '"searching"'
netifd: wan (9235): + uqmi -s -d /dev/cdc-wdm1 --get-serving-system
netifd: wan (9235): + registration='{"registration":"not_registered","plmn_mcc":208,"plmn_mnc":20,"plmn_description":"","roaming":true}'
netifd: wan (9235): + '[' -n  ]
netifd: wan (9235): + echo 'Starting network wan'

As the while loop checks only "searching" pattern, uqmi.sh script quits
searching loop and continues whereas the modem is not registered

Other issue, after X seconds modem stops searching.
netifd: wan (9213): + uqmi -s -d /dev/cdc-wdm0 --get-serving-system
netifd: wan (9213): + grep '"searching"'
netifd: wan (9213): + '[' -e /dev/cdc-wdm0 ]
netifd: wan (9213): + '[' 3 -lt 0 -o 0 '=' 0 ]
netifd: wan (9213): + let registration_timeout++
netifd: wan (9213): + sleep 1
netifd: wan (9213): + uqmi -s -d /dev/cdc-wdm0 --get-serving-system
netifd: wan (9213): + grep '"searching"'
netifd: wan (9213): + uqmi -s -d /dev/cdc-wdm0 --get-serving-system
netifd: wan (9213): + registration='{"registration":"not_registered"}'
netifd: wan (9213): + '[' -n  ]
netifd: wan (9213): + echo 'Starting network wan'
netifd: wan (9213): Starting network wan

If registration_timeout is not expired, registration can be restarted

Signed-off-by: Thomas Richard <thomas.richard@kontron.com>
Tested-by: Florian Eckert <fe@dev.tdt.de>

package/network/utils/uqmi/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=uqmi
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/uqmi.git

package/network/utils/uqmi/files/lib/netifd/proto/qmi.sh

@@ -209,19 +209,36 @@ proto_qmi_setup() {
 
 	uqmi -s -d "$device" --sync > /dev/null 2>&1
 
+	uqmi -s -d "$device" --network-register > /dev/null 2>&1
+
 	echo "Waiting for network registration"
+	sleep 1
 	local registration_timeout=0
-	while uqmi -s -d "$device" --get-serving-system | grep '"searching"' > /dev/null; do
-		[ -e "$device" ] || return 1
-		if [ "$registration_timeout" -lt "$timeout" -o "$timeout" = "0" ]; then
-			let registration_timeout++
-			sleep 1;
+	local registration_state=""
+	while true; do
+		registration_state=$(uqmi -s -d "$device" --get-serving-system 2>/dev/null | jsonfilter -e "@.registration" 2>/dev/null)
+
+		[ "$registration_state" = "registered" ] && break
+
+		if [ "$registration_state" = "searching" ] || [ "$registration_state" = "not_registered" ]; then
+			if [ "$registration_timeout" -lt "$timeout" ] || [ "$timeout" = "0" ]; then
+				[ "$registration_state" = "searching" ] || {
+					echo "Device stopped network registration. Restart network registration"
+					uqmi -s -d "$device" --network-register > /dev/null 2>&1
+				}
+				let registration_timeout++
+				sleep 1
+				continue
+			fi
+			echo "Network registration failed, registration timeout reached"
 		else
-			echo "Network registration failed"
-			proto_notify_error "$interface" NETWORK_REGISTRATION_FAILED
-			proto_block_restart "$interface"
-			return 1
+			# registration_state is 'registration_denied' or 'unknown' or ''
+			echo "Network registration failed (reason: '$registration_state')"
 		fi
+
+		proto_notify_error "$interface" NETWORK_REGISTRATION_FAILED
+		proto_block_restart "$interface"
+		return 1
 	done
 
 	[ -n "$modes" ] && uqmi -s -d "$device" --set-network-modes "$modes" > /dev/null 2>&1