[LEDE-DEV] ath9k stability in LEDE master branch - kernel panic every ~5 minutes

[Nick Lowe]

Hi Dave,

The hardware platform is 2 x AR9390 manufactured by Senao on an apu2c4.

01:00.0 "Network controller" "Qualcomm Atheros" "AR93xx Wireless
Network Adapter" -r01 "Qualcomm Atheros" "Device
 0205"

05:00.0 "Network controller" "Qualcomm Atheros" "AR93xx Wireless
Network Adapter" -r01 "Qualcomm Atheros" "Device
 3114"

I tried booting adding nocpu or maxcpus=0 to grub but this will not
boot. Would I have to use a build without SMP support? Do you have
another suggested method for achieving this?

I am using a build with Kernel 4.9.8 now and this crashes with kernel
panics such as:

LEDE Reboot SNAPSHOT r3386-0799de6 / LuCI Master (git-17.041.67116-1834eff)

[   85.116532] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   85.123276] br-lan: port 3(wlan0) entered blocking state
[   85.128841] br-lan: port 3(wlan0) entered forwarding state
[  338.599214] BUG: unable to handle kernel paging request at 0000000000015968
[  338.606286] IP: [<ffffffff81085b57>]
native_queued_spin_lock_slowpath+0x120/0x16c
[  338.613870] PGD 118888067 [  338.616419] PUD 11888a067
PMD 0 [  338.619725]
[  338.621271] Oops: 0002 [#1] SMP
[  338.624445] Modules linked in: ath9k ath9k_common pppoe ppp_async
ath9k_hw ath pppox ppp_generic nf_conntrack_
ipv6 mac80211 iptable_nat ipt_REJECT ipt_MASQUERADE cfg80211 xt_time
xt_tcpudp xt_state xt_nat xt_multiport xt_ma
rk xt_mac xt_limit xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT
xt_LOG xt_CT slhc r8169 nf_reject_ipv4 nf_nat_re
direct nf_nat_masquerade_ipv4 nf_conntrack_ipv4 nf_nat_ipv4 nf_nat
nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 nf_c
onntrack_rtcache nf_conntrack iptable_mangle iptable_filter ip_tables
e1000e crc_ccitt compat i2c_dev ip6t_REJECT
 nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_mangle
ip6table_filter ip6_tables x_tables igb i2c_algo_bit i2
c_core e1000 button_hotplug ptp pps_core mii
[  338.689162] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.8 #0
[  338.695044] Hardware name: PC Engines apu2/apu2, BIOS 6f1e98a-dirty
05/15/2016
[  338.702346] task: ffff88011a0a7080 task.stack: ffffc90000060000
[  338.708294] RIP: 0010:[<ffffffff81085b57>]  [<ffffffff81085b57>]
native_queued_spin_lock_slowpath+0x120/0x16c
[  338.718298] RSP: 0018:ffff88011ec83d88  EFLAGS: 00010202
[  338.723650] RAX: 000000000000065c RBX: ffff880118fd9858 RCX: 0000000000015968
[  338.730818] RDX: ffff88011ec95940 RSI: 0000000000080000 RDI: ffff880118fcb4d0
[  338.737994] RBP: ffff88011ec83e70 R08: 0000000000000001 R09: 0000000000000000
[  338.745160] R10: ffffc900015ef920 R11: ffff880119b8da00 R12: ffff880118745820
[  338.752326] R13: ffff88011ec83ec0 R14: ffff880119975500 R15: ffff880118fc9c20
[  338.759488] FS:  0000000000000000(0000) GS:ffff88011ec80000(0000)
knlGS:0000000000000000
[  338.767637] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  338.773411] CR2: 0000000000015968 CR3: 0000000118a82000 CR4: 00000000000406e0
[  338.780578] Stack:
[  338.782618]  ffffffff8143a9af ffffffffa0286c95 0000000000000000
0000000000000000
[  338.790155]  0000000000000000 0000000000000000 0000000000000400
ffff88011ec83ea0
[  338.797703]  ffffffff00000000 ffff880118fcb4b0 0000000000000000
ffff880118fc8de0
[  338.805235] Call Trace:
[  338.807718]  <IRQ> [  338.809670]  [<ffffffff8143a9af>] ?
_raw_spin_lock_bh+0x21/0x24
[  338.815662]  [<ffffffffa0286c95>] ? ath_tx_aggr_wakeup+0x1ed/0xafa [ath9k]
[  338.822583]  [<ffffffff8107f8f9>] ? load_balance+0x14e/0x6f8
[  338.828297]  [<ffffffffa0282c94>] ? __ath9k_flush+0x3a8/0x5fb [ath9k]
[  338.834787]  [<ffffffffa0287ffe>] ? ath_tx_edma_tasklet+0x2d0/0x2f8 [ath9k]
[  338.841796]  [<ffffffffa0281c73>] ? ath9k_tasklet+0x178/0x1d1 [ath9k]
[  338.848290]  [<ffffffff81060c1a>] ? tasklet_action+0x9f/0xa8
[  338.853985]  [<ffffffff81060e44>] ? __do_softirq+0xb8/0x1a1
[  338.859599]  [<ffffffff810610bc>] ? irq_exit+0x4f/0x5b
[  338.864777]  [<ffffffff810143ab>] ? do_IRQ+0xa4/0xba
[  338.869774]  [<ffffffff8143b53f>] ? common_interrupt+0x7f/0x7f
[  338.875643]  <EOI> [  338.877593]  [<ffffffff8132d26c>] ?
cpuidle_enter_state+0x134/0x189
[  338.883921]  [<ffffffff8132d225>] ? cpuidle_enter_state+0xed/0x189
[  338.890130]  [<ffffffff81084b96>] ? cpu_startup_entry+0x156/0x1c9
[  338.896262]  [<ffffffff810266d5>] ? start_secondary+0x12b/0x12e
[  338.902217] Code: e8 10 66 87 47 02 c1 e0 10 74 67 48 89 c1 c1 e8
12 48 c1 e9 0c ff c8 83 e1 30 48 98 48 81 c1
 40 59 01 00 48 03 0c c5 60 82 77 81 <48> 89 11 8b 42 08 85 c0 75 04
f3 90 eb f5 48 8b 0a 48 85 c9 74
[  338.922815] RIP  [<ffffffff81085b57>]
native_queued_spin_lock_slowpath+0x120/0x16c
[  338.930458]  RSP <ffff88011ec83d88>
[  338.933972] CR2: 0000000000015968
[  338.937322] ---[ end trace 6525cac670e9dcbc ]---
[  338.941968] Kernel panic - not syncing: Fatal exception in interrupt
[  338.948380] Kernel Offset: disabled
[  338.951898] Rebooting in 3 seconds..[  341.956062] ACPI MEMORY or
I/O RESET_REG.

Thanks,

Nick