[FS#45] TL WDR3500 crash during boot up

[LEDE Bugs]

The following task has a new comment added:

FS#45 - TL WDR3500 crash during boot up
User who did this - Piotr Dymacz (pepe2k)

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TP-Link TL-WR841N v9 + r1266, problem still exists, during first boot after flashing and later, during regular boots. Only one LAN cable attached.

Full log from serial console attached.

[   40.061171] ------------[ cut here ]------------
[   40.066020] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:306 dev_watchdog+0x1dc/0x260()
[   40.074752] NETDEV WATCHDOG: eth0 (ag71xx): transmit queue 0 timed out
[   40.081501] Modules linked in: ath9k ath9k_common pppoe ppp_async iptable_nat ath9k_hw ath pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv6 nf_conntrack_ipv4 mac80211 ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_nat xt_multiport xt_mark xt_mac xt_limit xt_id xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_CT slhc nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_nat nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack iptable_raw iptable_mangle iptable_filter ip_tables crc_ccitt compat ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_raw ip6table_mangle ip6table_filter ip6_tables x_tables gpio_button_hotplug
[   40.143925] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.15 #1
[   40.149857] Stack : 803de4e4 00000000 00000001 80430000 804291b8 80428e43 803bfb84 00000000
          80493798 804274dc 00000200 00100000 0000000a 800a6fbc 803c51e8 80420000
          00000003 804274dc 803c35f4 80423c2c 0000000a 800a4f38 00000006 00000000
          00000000 801f3a00 00000000 00000000 00000000 00000000 00000000 00000000
          00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
          ...
[   40.186897] Call Trace:
[   40.189439] [] show_stack+0x50/0x84
[   40.193968] [] warn_slowpath_common+0xa0/0xd0
[   40.199367] [] warn_slowpath_fmt+0x2c/0x38
[   40.204518] [] dev_watchdog+0x1dc/0x260
[   40.209404] [] call_timer_fn.isra.5+0x24/0x80
[   40.214819] [] run_timer_softirq+0x1b4/0x1fc
[   40.220134] [] __do_softirq+0x250/0x298
[   40.225024] [] plat_irq_dispatch+0xd4/0x10c
[   40.230243] [] ret_from_irq+0x0/0x4
[   40.234760] [] __r4k_wait+0x20/0x40
[   40.239268] [] cpu_startup_entry+0x9c/0xe8
[   40.244419] [] start_kernel+0x470/0x490
[   40.249277]
[   40.250820] ---[ end trace f47c5e34ff9de6a5 ]---
[   40.255597] eth0: tx timeout
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=45#comment207