[FS#441] Kernel crash: eth0 (ag71xx): transmit queue 0 timed out

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Johan van Zoomeren (amain) 

Attached to Project - LEDE Project
Summary - Kernel crash: eth0 (ag71xx): transmit queue 0 timed out
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - Device: TL-WR1043ND v1
LEDE: snapshot r3189-12db207

During a **simultaneous bidirectional** iperf load test, after about 20 minutes, the kernel crashes. I reproduced this several times:

Server 1  1043ND  Laptop via wireless N

LEDE is using a default setup. Only changes:
* Setting wireless encryption to psk with password
* Setting a DNAT rule for server 1 to be able reach the iperf server on the Laptop

This bug was actually discovered while testing fixes for FS#13 - Ath9k AP stays up for connected clients but doesn't show in scan on new ones

Serial console ouput:


[ 1294.022551] ------------[ cut here ]------------
[ 1294.027247] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:306 dev_watchdog+0x1dc/0x260()
[ 1294.035754] NETDEV WATCHDOG: eth0 (ag71xx): transmit queue 0 timed out
[ 1294.042319] Modules linked in: ath9k ath9k_common pppoe ppp_async ath9k_hw ath pppox ppp_generic nf_conntrack_ipv6 mac80211 iptable_nn
[ 1294.106287] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.45 #0
[ 1294.112066] Stack : 803e4844 00000000 00000001 80440000 8042f1dc 8042ee63 803c5e64 00000000
          804a378c 8042d4fc 00000200 00100000 0000000a 800a7618 803cb554 80430000
          00000003 8042d4fc 803c9960 81809e34 0000000a 800a5594 00000006 00000000
          00000000 801f5400 00000000 00000000 00000000 00000000 00000000 00000000
          00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
          ...
[ 1294.148122] Call Trace:
[ 1294.150617] [] vprintk_default+0x24/0x30
[ 1294.155474] [] printk+0x2c/0x38
[ 1294.159515] [] wait_for_xmitr+0x84/0xcc
[ 1294.164289] [] warn_slowpath_common+0xa0/0xd0
[ 1294.169564] [] dump_stack+0x14/0x28
[ 1294.173975] [] show_stack+0x50/0x84
[ 1294.178376] [] warn_slowpath_common+0xa0/0xd0
[ 1294.183661] [] dev_watchdog+0x1dc/0x260
[ 1294.188408] [] warn_slowpath_fmt+0x2c/0x38
[ 1294.193450] [] dev_watchdog+0x1dc/0x260
[ 1294.198191] [] dev_watchdog+0x0/0x260
[ 1294.202782] [] call_timer_fn.isra.5+0x24/0x80
[ 1294.208051] [] run_timer_softirq+0x1b4/0x1fc
[ 1294.213248] [] handle_irq_event_percpu+0x154/0x188
[ 1294.218960] [] __do_softirq+0x250/0x298
[ 1294.223721] [] handle_percpu_irq+0x50/0x80
[ 1294.228746] [] plat_irq_dispatch+0xd4/0x10c
[ 1294.233848] [] handle_int+0x134/0x140
[ 1294.238400] 
[ 1294.239904] ---[ end trace 17bad011a41ccba7 ]---
[ 1294.244567] eth0: tx timeout
[ 1299.022570] eth0: tx timeout
[ 1304.022581] eth0: tx timeout
[ 1309.022588] eth0: tx timeout


The eth0: tx timeout line is repeated every 5 seconds.


 

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=441