For the first time I just observed that wireless LAN failed on my Asus n55s.

I can assert that this hasn't been happening for weeks. It may be the first time this happens at all on this machine. Wireless LAN has always worked well, and now failing.

For the past hour and the half, dmesg spits around 30 messages per second burst rate, a repetition of 

Jun 29 13:00:29 n55sf-l kernel: [727461.166426] ath: phy0: Chip reset failed
Jun 29 13:00:29 n55sf-l kernel: [727461.166428] ath: phy0: Unable to reset channel, reset status -22
Jun 29 13:00:29 n55sf-l kernel: [727461.166432] ath: phy0: Unable to set channel
Jun 29 13:00:29 n55sf-l kernel: [727461.180256] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 13:00:29 n55sf-l kernel: [727461.180268] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 13:00:29 n55sf-l kernel: [727461.251940] ath: phy0: Failed to stop TX DMA, queues=0x10f!

FWIW, here are the first messages before that endless loop :


Jun 29 12:33:45 n55sf-l kernel: [725859.090225] irq 17: nobody cared (try booting with the "irqpoll" option)
Jun 29 12:33:45 n55sf-l kernel: [725859.090240] Pid: 0, comm: swapper/0 Tainted: G           O 3.5.0-34-generic #55-Ubuntu
Jun 29 12:33:45 n55sf-l kernel: [725859.090244] Call Trace:
Jun 29 12:33:45 n55sf-l kernel: [725859.090248]  <IRQ>  [<ffffffff810e1a8d>] __report_bad_irq+0x3d/0xe0
Jun 29 12:33:45 n55sf-l kernel: [725859.090269]  [<ffffffff810e1f52>] note_interrupt+0x1c2/0x210
Jun 29 12:33:45 n55sf-l kernel: [725859.090282]  [<ffffffff81391f8a>] ? intel_idle+0xea/0x150
Jun 29 12:33:45 n55sf-l kernel: [725859.090292]  [<ffffffff810df6f7>] handle_irq_event_percpu+0xa7/0x1f0
Jun 29 12:33:45 n55sf-l kernel: [725859.090300]  [<ffffffff810df88e>] handle_irq_event+0x4e/0x80
Jun 29 12:33:45 n55sf-l kernel: [725859.090307]  [<ffffffff810e2a8a>] handle_fasteoi_irq+0x5a/0x100
Jun 29 12:33:45 n55sf-l kernel: [725859.090319]  [<ffffffff81015072>] handle_irq+0x22/0x40
Jun 29 12:33:45 n55sf-l kernel: [725859.090328]  [<ffffffff8168c08a>] do_IRQ+0x5a/0xe0
Jun 29 12:33:45 n55sf-l kernel: [725859.090340]  [<ffffffff8168262a>] common_interrupt+0x6a/0x6a
Jun 29 12:33:45 n55sf-l kernel: [725859.090343]  <EOI>  [<ffffffff81391f8a>] ? intel_idle+0xea/0x150
Jun 29 12:33:45 n55sf-l kernel: [725859.090359]  [<ffffffff81391f6b>] ? intel_idle+0xcb/0x150
Jun 29 12:33:45 n55sf-l kernel: [725859.090371]  [<ffffffff81525f09>] cpuidle_enter+0x19/0x20
Jun 29 12:33:45 n55sf-l kernel: [725859.090378]  [<ffffffff81526549>] cpuidle_idle_call+0xa9/0x240
Jun 29 12:33:45 n55sf-l kernel: [725859.090386]  [<ffffffff8101c45f>] cpu_idle+0xaf/0x120
Jun 29 12:33:45 n55sf-l kernel: [725859.090394]  [<ffffffff8164f52e>] rest_init+0x72/0x74
Jun 29 12:33:45 n55sf-l kernel: [725859.090405]  [<ffffffff81cf3bf3>] start_kernel+0x3cf/0x3dc
Jun 29 12:33:45 n55sf-l kernel: [725859.090414]  [<ffffffff81cf3673>] ? do_early_param+0x91/0x91
Jun 29 12:33:45 n55sf-l kernel: [725859.090424]  [<ffffffff81cf3356>] x86_64_start_reservations+0x131/0x135
Jun 29 12:33:45 n55sf-l kernel: [725859.090432]  [<ffffffff81cf345a>] x86_64_start_kernel+0x100/0x10f
Jun 29 12:33:45 n55sf-l kernel: [725859.090436] handlers:
Jun 29 12:33:45 n55sf-l kernel: [725859.090458] [<ffffffffa03cf370>] ath_isr [ath9k]
Jun 29 12:33:45 n55sf-l kernel: [725859.090464] Disabling IRQ #17
Jun 29 12:33:46 n55sf-l wpa_supplicant[8690]: wlan0: CTRL-EVENT-DISCONNECTED bssid=e2:7d:2b:89:47:58 reason=4
Jun 29 12:33:46 n55sf-l kernel: [725859.398377] cfg80211: All devices are disconnected, going to restore regulatory settings
Jun 29 12:33:46 n55sf-l kernel: [725859.398388] cfg80211: Restoring regulatory settings
Jun 29 12:33:46 n55sf-l NetworkManager[1136]: <info> (wlan0): supplicant interface state: completed -> disconnected
Jun 29 12:33:46 n55sf-l kernel: [725859.406889] cfg80211: Ignoring regulatory request Set by core since the driver uses its own custom regulatory domain
Jun 29 12:33:46 n55sf-l kernel: [725859.406930] cfg80211: World regulatory domain updated:
Jun 29 12:33:46 n55sf-l kernel: [725859.406934] cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
Jun 29 12:33:46 n55sf-l kernel: [725859.406940] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
Jun 29 12:33:46 n55sf-l kernel: [725859.406945] cfg80211:   (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
Jun 29 12:33:46 n55sf-l kernel: [725859.406949] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
Jun 29 12:33:46 n55sf-l kernel: [725859.406953] cfg80211:   (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
Jun 29 12:33:46 n55sf-l kernel: [725859.406958] cfg80211:   (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
Jun 29 12:33:46 n55sf-l kernel: [725859.927455] ath: phy0: RX failed to go idle in 10 ms RXSM=0xffffffff
Jun 29 12:33:46 n55sf-l kernel: [725859.941833] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:46 n55sf-l kernel: [725859.953068] ath: phy0: Failed to wakeup in 500us
Jun 29 12:33:46 n55sf-l kernel: [725860.080681] ath: phy0: RX failed to go idle in 10 ms RXSM=0xffffffff
Jun 29 12:33:46 n55sf-l kernel: [725860.095067] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:46 n55sf-l kernel: [725860.106523] ath: phy0: Failed to wakeup in 500us
Jun 29 12:33:46 n55sf-l kernel: [725860.121129] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:46 n55sf-l kernel: [725860.121337] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 12:33:47 n55sf-l kernel: [725860.192400] ath: phy0: Failed to stop TX DMA, queues=0x10f!
Jun 29 12:33:47 n55sf-l NetworkManager[1136]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Jun 29 12:33:47 n55sf-l kernel: [725860.313940] ath: phy0: Chip reset failed
Jun 29 12:33:47 n55sf-l kernel: [725860.313942] ath: phy0: Unable to reset channel, reset status -22
Jun 29 12:33:47 n55sf-l kernel: [725860.313949] ath: phy0: Unable to set channel
Jun 29 12:33:47 n55sf-l kernel: [725860.328774] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:47 n55sf-l kernel: [725860.328853] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 12:33:47 n55sf-l kernel: [725860.402135] ath: phy0: Failed to stop TX DMA, queues=0x10f!
Jun 29 12:33:47 n55sf-l kernel: [725860.524528] ath: phy0: Chip reset failed
Jun 29 12:33:47 n55sf-l kernel: [725860.524536] ath: phy0: Unable to reset channel, reset status -22
Jun 29 12:33:47 n55sf-l kernel: [725860.524552] ath: phy0: Unable to set channel
Jun 29 12:33:47 n55sf-l kernel: [725860.538379] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:47 n55sf-l kernel: [725860.538442] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 12:33:47 n55sf-l kernel: [725860.611700] ath: phy0: Failed to stop TX DMA, queues=0x10f!
Jun 29 12:33:47 n55sf-l kernel: [725860.733297] ath: phy0: Chip reset failed
Jun 29 12:33:47 n55sf-l kernel: [725860.733305] ath: phy0: Unable to reset channel, reset status -22
Jun 29 12:33:47 n55sf-l kernel: [725860.733324] ath: phy0: Unable to set channel
Jun 29 12:33:47 n55sf-l kernel: [725860.746947] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:47 n55sf-l kernel: [725860.746972] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 12:33:47 n55sf-l kernel: [725860.819032] ath: phy0: Failed to stop TX DMA, queues=0x10f!
Jun 29 12:33:47 n55sf-l kernel: [725860.942818] ath: phy0: Chip reset failed
Jun 29 12:33:47 n55sf-l kernel: [725860.942820] ath: phy0: Unable to reset channel, reset status -22
Jun 29 12:33:47 n55sf-l kernel: [725860.942823] ath: phy0: Unable to set channel
Jun 29 12:33:47 n55sf-l kernel: [725860.957342] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 12:33:47 n55sf-l kernel: [725860.957364] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 12:33:47 n55sf-l kernel: [725861.034030] ath: phy0: Failed to stop TX DMA, queues=0x10f!

The machine still operates with wired Ethernet connection.

Interestingly, the loop pauses sometimes. You'll find attached the result of 

grep -o ^............... /var/log/kern.log | uniq -c

which shows some patterns in the number of log lines at each second.

The machine has not rebooted or anything, so if you think there's something I can do to help fix the bug, please ask.


Jun 29 14:00:30 n55sf-l kernel: [731057.433681] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 14:00:30 n55sf-l kernel: [731057.503686] ath: phy0: Failed to stop TX DMA, queues=0x10f!
Jun 29 14:00:30 n55sf-l kernel: [731057.625638] ath: phy0: Chip reset failed
Jun 29 14:00:30 n55sf-l kernel: [731057.625647] ath: phy0: Unable to reset channel, reset status -22
Jun 29 14:00:30 n55sf-l kernel: [731057.625663] ath: phy0: Unable to set channel
Jun 29 14:02:26 n55sf-l kernel: [731174.236655] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
Jun 29 14:02:26 n55sf-l kernel: [731174.236665] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
Jun 29 14:02:27 n55sf-l kernel: [731174.311893] ath: phy0: Failed to stop TX DMA, queues=0x10f!
Jun 29 14:02:27 n55sf-l kernel: [731174.433342] ath: phy0: Chip reset failed
Jun 29 14:02:27 n55sf-l kernel: [731174.433345] ath: phy0: Unable to reset channel, reset status -22
Jun 29 14:02:27 n55sf-l kernel: [731174.433349] ath: phy0: Unable to set channel
Jun 29 14:02:27 n55sf-l kernel: [731174.446896] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW