aa777888
Posts: 5
Joined: Wed Dec 28, 2016 1:53 am

DWA-171 unable to handle kernel paging request (Pi3)

Mon Jan 02, 2017 8:09 pm

MrEngman--I'm very much hoping that you can help me.

Access point is a Ubiquiti UAP LC AR. Addressing is static.

Hardware is a Pi3 and DWA-171.

uname -a returns:

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Linux radiopi 4.4.34-v7+ #930 SMP Wed Nov 23 15:20:41 GMT 2016 armv7l GNU/Linux
I initially used this link to install:

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wget https://dl.dropboxusercontent.com/u/80256631/install-wifi.tar.gz
When I had the problems described below, I reinstalled using this link:

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wget https://dl.dropboxusercontent.com/u/80256631/8812au-4.4.34-v7-930.tar.gz
However in both cases I get the same behavior.

The DWA-171 will come up at boot time no problem. iwconfig reports:

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wlan0     IEEE 802.11AC  ESSID:"noneofyourbusiness"  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency:5.745 GHz  Access Point: 82:2A:A8:85:83:4A
          Bit Rate:434 Mb/s   Sensitivity:0/0
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=75/100  Signal level=90/100  Noise level=0/100
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
iperf3 gives good results, usually in the 15 to 18Mbyte/s range.

However, after random periods, sometimes many hours, other times 30 seconds, the WiFi will go down. Sometimes it seems traffic dependent, i.e. if the Pi is just sitting there doing nothing it'll be OK, but start moving traffic (e.g. iperf3 testing) it will go down. Other times I can run iperf3 for hours and it is fine.

dmesg reports the following

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[   77.636093] RTL871X: rtw_set_802_11_connect(wlan0)  fw_state=0x00000009
[   77.651879] Unable to handle kernel paging request at virtual address bc4a301f
[   77.651907] pgd = 80004000
[   77.651918] [bc4a301f] *pgd=36b4c811, *pte=00000000, *ppte=00000000
[   77.651948] Internal error: Oops: 7 [#1] SMP ARM
[   77.651960] Modules linked in: bnep hci_uart btbcm bluetooth 8812au(O) cfg80211 rfkill snd_usb_audio snd_hwdep snd_usbmidi_lib snd_rawmidi snd_seq_device snd_bcm2835 snd_pcm snd_timer snd bcm2835_wdt bcm2835_gpiomem evdev joydev uio_pdrv_genirq uio rpi_backlight rpi_ft5406 i2c_dev fuse ipv6
[   77.652133] CPU: 2 PID: 425 Comm: RTW_CMD_THREAD Tainted: G           O    4.4.34-v7+ #930
[   77.652148] Hardware name: BCM2709
[   77.652170] task: b93a0b80 ti: b8a38000 task.ti: b8a38000
[   77.652697] PC is at join_cmd_hdl+0x168/0x370 [8812au]
[   77.652710] LR is at 0x0
[   77.652723] pc : [<7f26a004>]    lr : [<00000000>]    psr: 80000013
sp : b8a39ed8  ip : 00000000  fp : b8a39f14
[   77.652737] r10: 00000001  r9 : 7f34d130  r8 : bc4a140c
[   77.652747] r7 : bc49f0fe  r6 : bc4a301f  r5 : 00003ea9  r4 : bc49e000
[   77.652758] r3 : 00003f21  r2 : 00000001  r1 : bc49f1b2  r0 : 00000001
[   77.652771] Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[   77.652782] Control: 10c5383d  Table: 391d406a  DAC: 00000055
[   77.652794] Process RTW_CMD_THREAD (pid: 425, stack limit = 0xb8a38210)
[   77.652806] Stack: (0xb8a39ed8 to 0xb8a3a000)
[   77.652818] 9ec0:                                                       805bba64 800d989c
[   77.652835] 9ee0: afe74a9c afe74a80 b8a39f14 afe74a80 bc49e000 bc49f958 bc49f978 ffffa922
[   77.652852] 9f00: bc49f958 000048a4 b8a39f5c b8a39f18 7f246b5c 7f269ea8 b8a39f3c b8a38000
[   77.652869] 9f20: b684ca00 bc49f968 bc49f9a4 b8af4a00 00000000 00000000 b684ca00 bc49e000
[   77.652885] 9f40: 7f2468cc 00000000 00000000 00000000 b8a39fac b8a39f60 80042860 7f2468d8
[   77.652902] 9f60: 39713000 00000000 b8a39f94 bc49e000 00000000 00000000 b8a39f78 b8a39f78
[   77.652919] 9f80: 00000000 00000000 b8a39f88 b8a39f88 b684ca00 80042774 00000000 00000000
[   77.652935] 9fa0: 00000000 b8a39fb0 8000fbc8 80042780 00000000 00000000 00000000 00000000
[   77.652951] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   77.652967] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 124b002c 10802006
[   77.653821] [<7f26a004>] (join_cmd_hdl [8812au]) from [<7f246b5c>] (rtw_cmd_thread+0x290/0x3ec [8812au])
[   77.654247] [<7f246b5c>] (rtw_cmd_thread [8812au]) from [<80042860>] (kthread+0xec/0x104)
[   77.654273] [<80042860>] (kthread) from [<8000fbc8>] (ret_from_fork+0x14/0x2c)
[   77.654291] Code: e0888005 e59f9208 e2853078 e0876003 (e7d73003) 
[   77.654307] ---[ end trace a355fcd6d086b7c1 ]---
[   92.272130] RTL871X: rtw_set_802_11_connect(wlan0)  fw_state=0x00000008
I feel like I am very close to having this working reliably. I have searched extensively on the forum and elsewhere but have found no useful links to a solution for this problem. What am I missing?

Thanks,

aa

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