Xiaomi WiFi Router 3G

Thanks. I guess it is time to move from Padavan to LEDE back again.

Hello,

Someone can advise? From Total Commander I was able to login to the FTP server as root. From Windows Explorer it says (550 error code failed to change directory) basically I have no permission to open the remote folders.

Latest snapshot was quite unstable here. Network works fine, but internet drops several times a day and I have to reboot to get back to work.

Edit: It's totally unusable here. :confused:

Mon Jul  2 18:35:07 2018 kern.info kernel: [  155.765916] mtk_soc_eth 1e100000.ethernet: PPE started
Mon Jul  2 18:35:26 2018 daemon.info hostapd: wlan1: STA 8c:f5:a3:2c:55:8e IEEE 802.11: authenticated
Mon Jul  2 18:35:26 2018 daemon.info hostapd: wlan1: STA 8c:f5:a3:2c:55:8e IEEE 802.11: associated (aid 2)
Mon Jul  2 18:35:26 2018 daemon.notice hostapd: wlan1: AP-STA-CONNECTED 8c:f5:a3:2c:55:8e
Mon Jul  2 18:35:26 2018 daemon.info hostapd: wlan1: STA 8c:f5:a3:2c:55:8e WPA: pairwise key handshake completed (RSN)
Mon Jul  2 18:35:27 2018 daemon.info dnsmasq-dhcp[4775]: DHCPDISCOVER(br-lan) 8c:f5:a3:2c:55:8e
Mon Jul  2 18:35:27 2018 daemon.info dnsmasq-dhcp[4775]: DHCPOFFER(br-lan) 10.0.0.70 8c:f5:a3:2c:55:8e
Mon Jul  2 18:35:28 2018 daemon.info dnsmasq-dhcp[4775]: DHCPDISCOVER(br-lan) 8c:f5:a3:2c:55:8e
Mon Jul  2 18:35:28 2018 daemon.info dnsmasq-dhcp[4775]: DHCPOFFER(br-lan) 10.0.0.70 8c:f5:a3:2c:55:8e
Mon Jul  2 18:35:28 2018 daemon.info dnsmasq-dhcp[4775]: DHCPREQUEST(br-lan) 10.0.0.70 8c:f5:a3:2c:55:8e
Mon Jul  2 18:35:28 2018 daemon.info dnsmasq-dhcp[4775]: DHCPACK(br-lan) 10.0.0.70 8c:f5:a3:2c:55:8e S7
Mon Jul  2 18:36:02 2018 daemon.err uhttpd[2306]: luci: accepted login on / for root from 10.0.0.70
Mon Jul  2 18:36:08 2018 kern.err kernel: [  216.119632] mtk_soc_eth 1e100000.ethernet eth0: transmit timed out
Mon Jul  2 18:36:08 2018 kern.info kernel: [  216.125861] mtk_soc_eth 1e100000.ethernet eth0: dma_cfg:80000067
Mon Jul  2 18:36:08 2018 kern.info kernel: [  216.131970] mtk_soc_eth 1e100000.ethernet eth0: tx_ring=0, base=0d2b0000, max=0, ctx=3072, dtx=0, fdx=0, next=3072
Mon Jul  2 18:36:08 2018 kern.info kernel: [  216.142382] mtk_soc_eth 1e100000.ethernet eth0: rx_ring=0, base=0ee90000, max=0, calc=667, drx=668
Mon Jul  2 18:36:08 2018 daemon.notice miniupnpd[2547]: http://10.0.0.11:5000/rootDesc.xml not found, responding ERROR 404
Mon Jul  2 18:36:08 2018 daemon.notice miniupnpd[2547]: http://10.0.0.11:5000/rootDesc.xml not found, responding ERROR 404
Mon Jul  2 18:36:08 2018 daemon.notice miniupnpd[2547]: http://10.0.0.11:5000/rootDesc.xml not found, responding ERROR 404
Mon Jul  2 18:36:08 2018 kern.info kernel: [  216.568245] mtk_soc_eth 1e100000.ethernet: 0x100 = 0x5d60000c, 0x10c = 0x80818
Mon Jul  2 18:36:08 2018 kern.info kernel: [  216.581868] mtk_soc_eth 1e100000.ethernet: PPE started
Mon Jul  2 18:36:48 2018 kern.err kernel: [  256.119289] mtk_soc_eth 1e100000.ethernet eth0: transmit timed out
Mon Jul  2 18:36:48 2018 kern.info kernel: [  256.125485] mtk_soc_eth 1e100000.ethernet eth0: dma_cfg:80000067
Mon Jul  2 18:36:48 2018 kern.info kernel: [  256.131496] mtk_soc_eth 1e100000.ethernet eth0: tx_ring=0, base=0c120000, max=0, ctx=3072, dtx=0, fdx=0, next=3072
Mon Jul  2 18:36:48 2018 kern.info kernel: [  256.141825] mtk_soc_eth 1e100000.ethernet eth0: rx_ring=0, base=0d960000, max=0, calc=746, drx=747
Mon Jul  2 18:36:48 2018 kern.info kernel: [  256.563903] mtk_soc_eth 1e100000.ethernet: 0x100 = 0x5860000c, 0x10c = 0x80818
Mon Jul  2 18:36:48 2018 kern.info kernel: [  256.576955] mtk_soc_eth 1e100000.ethernet: PPE started
Mon Jul  2 18:36:50 2018 daemon.notice netifd: wan (1624): udhcpc: sending renew to 189.7.40.42
Mon Jul  2 18:36:50 2018 daemon.notice netifd: wan (1624): udhcpc: received SIGTERM
Mon Jul  2 18:36:50 2018 daemon.notice netifd: Interface 'wan' is now down
Mon Jul  2 18:36:50 2018 daemon.err miniupnpd[2547]: ioctl(s, SIOCGIFADDR, ...): Address not available
Mon Jul  2 18:36:50 2018 daemon.err miniupnpd[2547]: Failed to get IP for interface eth0.2
Mon Jul  2 18:36:50 2018 daemon.warn miniupnpd[2547]: SendNATPMPPublicAddressChangeNotification: cannot get public IP address, stopping
Mon Jul  2 18:36:50 2018 daemon.notice netifd: Interface 'wan' is setting up now
Mon Jul  2 18:36:50 2018 user.notice SQM: Stopping SQM on wlan0-1
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: reading /tmp/resolv.conf.auto
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzzpooeaz-france.com
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzzezeroe.fr
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zztxdown.com
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzshw.net
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzpxw.cn
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzmyw.com
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzha.net
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using local addresses only for domain zzdsfy.com
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.222.222#53
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.220.220#53
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using nameserver 1.1.1.1#53
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using nameserver 1.0.0.1#53
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using nameserver 2606:4700:4700::1111#53
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using nameserver 2606:4700:4700::1001#53
Mon Jul  2 18:36:50 2018 daemon.info dnsmasq[4775]: using 23596 more local addresses
Mon Jul  2 18:36:50 2018 daemon.notice netifd: wan (5416): udhcpc: started, v1.28.4
Mon Jul  2 18:36:50 2018 daemon.notice netifd: wan (5416): udhcpc: sending discover
Mon Jul  2 18:36:51 2018 user.notice ddns-scripts[3813]: duckdns: PID '3813' terminated by 'SIGTERM' at 2018-07-02 18:36
Mon Jul  2 18:36:52 2018 user.info adblock-[3.5.3]: start adblock processing (start)
Mon Jul  2 18:36:53 2018 daemon.notice netifd: wan (5416): udhcpc: sending discover
Mon Jul  2 18:36:54 2018 daemon.info hostapd: wlan0: STA 7c:49:eb:15:77:67 IEEE 802.11: authenticated
Mon Jul  2 18:36:54 2018 daemon.info hostapd: wlan0: STA 7c:49:eb:15:77:67 IEEE 802.11: associated (aid 3)
Mon Jul  2 18:36:54 2018 daemon.notice hostapd: wlan0: AP-STA-CONNECTED 7c:49:eb:15:77:67
Mon Jul  2 18:36:54 2018 daemon.info hostapd: wlan0: STA 7c:49:eb:15:77:67 WPA: pairwise key handshake completed (RSN)
Mon Jul  2 18:36:55 2018 daemon.notice netifd: wan (5416): udhcpc: received SIGTERM
Mon Jul  2 18:36:55 2018 daemon.notice netifd: Interface 'wan' is now down
Mon Jul  2 18:36:58 2018 daemon.info dnsmasq-dhcp[4775]: DHCPDISCOVER(br-lan) 7c:49:eb:15:77:67
Mon Jul  2 18:36:58 2018 daemon.info dnsmasq-dhcp[4775]: DHCPOFFER(br-lan) 10.0.0.233 7c:49:eb:15:77:67
Mon Jul  2 18:36:58 2018 daemon.info dnsmasq-dhcp[4775]: DHCPDISCOVER(br-lan) 7c:49:eb:15:77:67
Mon Jul  2 18:36:58 2018 daemon.info dnsmasq-dhcp[4775]: DHCPOFFER(br-lan) 10.0.0.233 7c:49:eb:15:77:67
Mon Jul  2 18:36:58 2018 daemon.info dnsmasq-dhcp[4775]: DHCPREQUEST(br-lan) 10.0.0.233 7c:49:eb:15:77:67
Mon Jul  2 18:36:58 2018 daemon.info dnsmasq-dhcp[4775]: DHCPACK(br-lan) 10.0.0.233 7c:49:eb:15:77:67 yeelink-light-color2_miio87152212
Mon Jul  2 18:37:02 2018 daemon.notice netifd: Interface 'wan' is setting up now
Mon Jul  2 18:37:02 2018 daemon.notice netifd: wan (5911): udhcpc: started, v1.28.4
Mon Jul  2 18:37:02 2018 daemon.notice netifd: wan (5911): udhcpc: sending discover
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: read /etc/hosts - 4 addresses
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: read /tmp/hosts/odhcpd - 2 addresses
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: read /tmp/hosts/dhcp.cfg01411c - 14 addresses
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq-dhcp[4775]: read /etc/ethers - 0 addresses
Mon Jul  2 18:37:03 2018 user.info adblock-[3.5.3]: blocklist with overall 0 domains loaded successfully (Xiaomi Mi Router 3G, OpenWrt SNAPSHOT r7360-e15565a)
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain test
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain onion
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain localhost
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain local
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain invalid
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain bind
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using local addresses only for domain lan
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.222.222#53
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.220.220#53
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using nameserver 1.1.1.1#53
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using nameserver 1.0.0.1#53
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using nameserver 2606:4700:4700::1111#53
Mon Jul  2 18:37:03 2018 daemon.info dnsmasq[4775]: using nameserver 2606:4700:4700::1001#53
Mon Jul  2 18:37:05 2018 daemon.notice netifd: wan (5911): udhcpc: sending discover
Mon Jul  2 18:37:08 2018 daemon.notice netifd: wan (5911): udhcpc: sending discover
Mon Jul  2 18:37:16 2018 daemon.notice netifd: wan (5911): udhcpc: received SIGTERM
Mon Jul  2 18:37:16 2018 daemon.notice netifd: Interface 'wan' is now down
Mon Jul  2 18:37:22 2018 daemon.notice netifd: Interface 'wan6' is now down
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: read /etc/hosts - 4 addresses
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: read /tmp/hosts/odhcpd - 1 addresses
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: read /tmp/hosts/dhcp.cfg01411c - 14 addresses
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq-dhcp[4775]: read /etc/ethers - 0 addresses
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain test
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain onion
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain localhost
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain local
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain invalid
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain bind
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain lan
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.222.222#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.220.220#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 1.1.1.1#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 1.0.0.1#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 2606:4700:4700::1111#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 2606:4700:4700::1001#53
Mon Jul  2 18:37:23 2018 daemon.notice netifd: Interface 'wan' is disabled
Mon Jul  2 18:37:23 2018 daemon.notice netifd: Interface 'wan6' is disabled
Mon Jul  2 18:37:23 2018 daemon.notice netifd: VLAN 'eth0.2' link is down
Mon Jul  2 18:37:23 2018 daemon.notice netifd: Interface 'wan' has link connectivity loss
Mon Jul  2 18:37:23 2018 daemon.notice netifd: Interface 'wan6' has link connectivity loss
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: reading /tmp/resolv.conf.auto
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain test
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain onion
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain localhost
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain local
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain invalid
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain bind
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using local addresses only for domain lan
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.222.222#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 208.67.220.220#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 1.1.1.1#53
Mon Jul  2 18:37:23 2018 daemon.info dnsmasq[4775]: using nameserver 1.0.0.1#53
Mon Jul  2 18:37:29 2018 daemon.notice netifd: Interface 'wan' is enabled
Mon Jul  2 18:37:29 2018 daemon.notice netifd: Interface 'wan6' is enabled
Mon Jul  2 18:37:29 2018 daemon.notice netifd: VLAN 'eth0.2' link is up
Mon Jul  2 18:37:29 2018 daemon.notice netifd: Interface 'wan' has link connectivity
Mon Jul  2 18:37:29 2018 daemon.notice netifd: Interface 'wan6' has link connectivity
Mon Jul  2 18:37:29 2018 daemon.notice netifd: Interface 'wan6' is setting up now
Mon Jul  2 18:37:29 2018 daemon.err odhcp6c[6115]: Failed to send RS (Address not available)
Mon Jul  2 18:37:29 2018 daemon.err odhcp6c[6115]: Failed to send DHCPV6 message to ff02::1:2 (Address not available)
Mon Jul  2 18:37:30 2018 daemon.err odhcp6c[6115]: Failed to send DHCPV6 message to ff02::1:2 (Address not available)
Mon Jul  2 18:37:32 2018 daemon.notice netifd: Interface 'wan' is setting up now
Mon Jul  2 18:37:32 2018 daemon.notice netifd: wan (6208): udhcpc: started, v1.28.4
Mon Jul  2 18:37:32 2018 daemon.notice netifd: wan (6208): udhcpc: sending discover

Whats wrong?

Really?

Tell us what is wrong! Nobody reads logs for fun :smiley:

At minimum you should provide us some more information on your internet connection...

1 Like

Sorry, my question was in the post above.
This:

Latest snapshot was quite unstable here. Network works fine, but internet drops several times a day and I have to reboot to get back to work.

Edit: It's totally unusable here.

EDIT: I updated to 7374, I'm testing now, but his package (http://downloads.lede-project.org/snapshots/faillogs/mipsel_24kc/packages/nfs-kernel-server/) not available.

EDIT 2: Problem persists. I changed the router until a solution.

@Filipz which snapshot are you using? I also got instable 2.4G wifi :confused:

did anyone try the 18.06 rc1 release already?
https://downloads.openwrt.org/releases/18.06.0-rc1/targets/ramips/mt7621/
i flashed it but did not test it till now

My problems are solved using this RC version:

https://downloads.openwrt.org/releases/18.06.0-rc1/targets/ramips/mt7621/

https://downloads.openwrt.org/snapshots/targets/ramips/mt7621/
The above link is 17.01.4 ?

RC1 is very good! No problems with wi-fi at all. Flashed from padavan.

I've been following this thread for months, not flashing because of reported issues. Is RC1 ready for use as main router? What I need:

  1. High reliability
  2. 2.4+5g wifi network, wired network. Care both about bw and latency.
  3. port forwarding
  4. DHCP

Pretty much that's it. Would most likely want to run the bufferbloat package as well.

The 2.4G wifi seems to work much better now however there are still sometimes problems when under full signal I can't ping the router.

Pinging 192.168.2.1 with 32 bytes of data:
Reply from 192.168.2.1: bytes=32 time=3ms TTL=64
Request timed out.
Request timed out.
Request timed out.

There are also problems with my Huawei E3372 HiLink LTE modem. With strong LTE signal from time to time I need to re-connect in order to get network back.

When you can't ping the router is internet access also broken?

Looks like the problem was 2.4G wifi channel. When changed from 5 to 13 now it seems to work ok.

Hey there, with the RC1 release I finally found courage to flash my mir3g, but I haven't found any instructions on how to make a sufficient buckup. Someone care to share steps for it?

After upgrade from r7200-2f3c5fe to r7313-4b50854 (on 2018-06-26) I've encountered twice a similar issue that @Flipz mentioned (as I see in logs he provided). An error which breaks my WAN connectivity.

When it happens I'm able to SSH to mir3g from my WLAN (2.4 GHz) and reboot cleanly with 'reboot' command which brings back the Internet connectivity.

First occurence of this issue was maybe half an hour after the upgrade to r7313, second one was today (so several days later, router was working continuously and flawlessly between these incidents, however it was restarted a couple of times due to power outages). I haven't noticed any real issues since r6719-a656ea0, up to the moment of the upgrade mentioned at the beginning of my post.

Logs from today:

Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.737595] ------------[ cut here ]------------
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.742331] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:320 dev_watchdog+0x1ac/0x324
Sat Jul  7 15:02:43 2018 kern.info kernel: [118721.750672] NETDEV WATCHDOG: eth0 (mtk_soc_eth): transmit queue 0 timed out
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.757708] Modules linked in: pppoe ppp_async pppox ppp_generic nf_conntrack_ipv6 mt76x2e mt7603e mt76 mac80211 iptable_nat ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_nat xt_multiport xt_mark xt_mac xt_limit xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_FLOWOFFLOAD xt_CT slhc nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_conntrack_ipv4 nf_nat_ipv4 nf_nat nf_log_ipv4 nf_flow_table_hw nf_flow_table nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack iptable_mangle iptable_filter ip_tables crc_ccitt compat ledtrig_usbport ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables x_tables leds_gpio xhci_mtk xhci_plat_hcd xhci_pci xhci_hcd gpio_button_hotplug usbcore nls_base usb_common
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.826266] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.50 #0
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.832336] Stack : 00000000 00000000 00000000 00000000 80607ad2 00000034 00000000 00000000
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.840758]         8fc441f4 8059c947 805275ac 00000001 00000000 00000001 8fc0dd68 1cc282d2
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.849179]         00000000 00000000 80600000 00006350 00000000 0000013d 00000007 00000000
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.857602]         00000000 805a0000 000c9b9a 70617773 00000000 00000000 805c0000 80376768
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.866036]         00000009 00000140 00000001 8fe13040 00000000 80299e30 00000004 80600004
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.874454]         ...
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.876979] Call Trace:
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.879527] [<80010558>] show_stack+0x58/0x100
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.884052] [<804685ac>] dump_stack+0x9c/0xe0
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.888483] [<8002e218>] __warn+0xe0/0x114
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.892645] [<8002e27c>] warn_slowpath_fmt+0x30/0x3c
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.897680] [<80376768>] dev_watchdog+0x1ac/0x324
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.902467] [<800861c4>] call_timer_fn.isra.3+0x24/0x84
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.907757] [<800863dc>] run_timer_softirq+0x1b8/0x244
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.912973] [<80485870>] __do_softirq+0x128/0x2ec
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.917753] [<80032920>] irq_exit+0x98/0xcc
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.922024] [<8024a82c>] plat_irq_dispatch+0xfc/0x138
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.927142] [<8000b5a8>] except_vec_vi_end+0xb8/0xc4
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.932176] [<8000cf70>] r4k_wait_irqoff+0x1c/0x24
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.937058] [<8006647c>] do_idle+0xe4/0x168
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.941316] [<800666f8>] cpu_startup_entry+0x24/0x2c
Sat Jul  7 15:02:43 2018 kern.warn kernel: [118721.946403] ---[ end trace cd0b23207b7a284d ]---
Sat Jul  7 15:02:43 2018 kern.err kernel: [118721.951105] mtk_soc_eth 1e100000.ethernet eth0: transmit timed out
Sat Jul  7 15:02:43 2018 kern.info kernel: [118721.957348] mtk_soc_eth 1e100000.ethernet eth0: dma_cfg:80000067
Sat Jul  7 15:02:43 2018 kern.info kernel: [118721.963444] mtk_soc_eth 1e100000.ethernet eth0: tx_ring=0, base=0eaa0000, max=0, ctx=2720, dtx=2716, fdx=2707, next=2720
Sat Jul  7 15:02:43 2018 kern.info kernel: [118721.974392] mtk_soc_eth 1e100000.ethernet eth0: rx_ring=0, base=0e240000, max=0, calc=3111, drx=3112
Sat Jul  7 15:02:43 2018 kern.info kernel: [118722.380898] mtk_soc_eth 1e100000.ethernet: 0x100 = 0x4f60040c, 0x10c = 0x80818
Sat Jul  7 15:02:43 2018 kern.info kernel: [118722.394017] mtk_soc_eth 1e100000.ethernet: PPE started
Sat Jul  7 15:07:44 2018 user.err ddns-scripts[2398]: duckdns: BusyBox nslookup error: '1'
Sat Jul  7 15:07:44 2018 user.warn ddns-scripts[2398]: duckdns: Get registered/public IP for '*.duckdns.org' failed - retry 1/0 in 60 seconds

Today I've upgraded r7313 to r7406-10e3932 and I'll wait to see if this changes anything (all of my testing is done on official binary snapshot builds from https://downloads.openwrt.org/snapshots/targets/ramips/mt7621/).

https://wiki.openwrt.org/doc/howto/generic.sysupgrade

the config is saved if you tick "keep settings"

all packets you installed with opkg are lost, you have to reinstall them after the sysupgrade if you use the normal image

Thanks for the answer, but I'm afraid that I wasn't clear enough with my question. My circumstance is upgrading stock router to LEDE, I already read the whole thread and checked a guide by @dissent1, but I believe it does not cover how to backup factory(stock) partitions and which partitions to backup.

@fakeful, basically the standard procedure, where you touch only one kernel ("kernel1") partition lets you revert to stock using the procedure described for example by @juppin in post #993.

You may of course backup the contents of all of the /dev/mtd* devices listed in /proc/mtd before flashing OpenWrt, however without serial access this might not be very useful and generally is not required to revert to stock FW.