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#1 2011-05-14 21:50:13

akb825
Member
Registered: 2011-03-27
Posts: 81

ath9k slow an unreliable; carl9170 randomly stalls

I've been trying (unsuccessfully) for months to get reliable wireless on a desktop. I have tried three different cards, each with different chipsets.

The one I would like to get working most is the D-Link DWA-556, which is based on the ath9k chipset AR5416+AR2133. (http://www.dlink.com/products/?pid=549) I specifically bought this card after looking online for what seemed to be the most compatible wireless N card for Linux after having problems with my previous cards. Everything seemed to point to the drivers being of decent quality and having it work without too much effort. Boy, was that wrong.

Most of the time it will fail to grab the address from DHCP. Sometimes it will connect successfully, but it is incredibly slow. Running online broadband speed tests will typically show speeds of around 0.5 Mbps, and local file transfers are around 500 KBps.

Looking online, I saw this kernel bug (https://bugzilla.kernel.org/show_bug.cgi?id=31452), but the fix was committed in 2.6.38.5 and I am currently on 2.6.38.6. There were other posts online recommending disabling hardware encryption with the ath9k module option "nohwcrypt=1", but that didn't seem to fix it. In fact, after disabling hardware encryption it seemed to make it more likely for DHCP to time out, and that persisted even after re-enabling hardware encryption and even rebooting. I also tried to install compat-wireless-patched and compat-wireless-patched-daily from AUR to no effect. (normal compat-wireless fails to compile...)

Here are the messages in everything.log when it fails to connect:

May 14 13:55:40 localhost kernel: [  981.483682] ADDRCONF(NETDEV_UP): wlan0: link is not ready
May 14 13:55:43 localhost kernel: [  984.405389] wlan0: authenticate with 00:18:e7:ef:ea:9e (try 1)
May 14 13:55:43 localhost kernel: [  984.411455] wlan0: authenticated
May 14 13:55:43 localhost kernel: [  984.411475] wlan0: associate with 00:18:e7:ef:ea:9e (try 1)
May 14 13:55:43 localhost kernel: [  984.609945] wlan0: associate with 00:18:e7:ef:ea:9e (try 2)
May 14 13:55:43 localhost kernel: [  984.622492] wlan0: RX AssocResp from 00:18:e7:ef:ea:9e (capab=0x431 status=0 aid=1)
May 14 13:55:43 localhost kernel: [  984.622494] wlan0: associated
May 14 13:55:43 localhost kernel: [  984.624830] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
May 14 13:55:45 localhost avahi-daemon[1786]: Registering new address record for fe80::5ed9:98ff:feb1:39fe on wlan0.*.
May 14 13:55:49 localhost dhcpcd[1873]: version 5.2.12 starting
May 14 13:55:49 localhost dhcpcd[1873]: wlan0: rebinding lease of 192.168.0.104
May 14 13:55:54 localhost kernel: [  995.056604] wlan0: no IPv6 routers present
May 14 13:55:59 localhost dhcpcd[1873]: timed out
May 14 13:55:59 localhost avahi-daemon[1786]: Withdrawing address record for fe80::5ed9:98ff:feb1:39fe on wlan0.
May 14 13:55:59 localhost kernel: [ 1000.574481] wlan0: deauthenticating from 00:18:e7:ef:ea:9e by local choice (reason=3)
May 14 13:55:59 localhost kernel: [ 1000.605166] cfg80211: Calling CRDA to update world regulatory domain
May 14 13:55:59 localhost kernel: [ 1000.605502] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready

My fallback is what I was using before, which is a USB wireless N dongle based on the ar9170 chipset. (http://www.iogear.com/product/GWU623/) It mostly works alright, if a little slow for my tastes for local file transfers, (around 2.5 MBps) but the big problem is the network will sometimes stall for a couple minutes. There don't appear to be any messages in the logs when this happens, and iwconfig and ifconfig still say that it's connected, but any attempts to access the network fail until it comes back in a couple minutes.

Any help would be greatly appreciated. To say this has been frustrating is a great understatement.

Last edited by akb825 (2011-05-15 09:08:38)

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#2 2011-05-14 23:15:08

MadCat_X
Member
Registered: 2009-10-08
Posts: 189

Re: ath9k slow an unreliable; carl9170 randomly stalls

You do not mention any details about the network you're connecting to. Can it possibly be a problem with the access point rather than your computer? Does it work when you set the IP statically with dhcpcd daemon disabled? Do you use any connection management tools like NetworkManager or wicd?
All I can say is that wireless has never been a problem for me, I have an Intel-based adapter though.

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#3 2011-05-14 23:56:14

akb825
Member
Registered: 2011-03-27
Posts: 81

Re: ath9k slow an unreliable; carl9170 randomly stalls

I have a laptop running Mac OS X that connects to my wireless network just fine, so I don't think it's the access point. I just tried with a static IP with the D-Link card, and though that allows me to connect, it is still horribly slow. I am using WPA2 encryption for my wireless network, but I tried disabling encryption from my router and that didn't seem to change anything. Forcing my router to use wireless G instead of N didn't make any difference, either. I looked to see if I could force my wireless card to use G, but I couldn't find anything except for manually setting the bitrate.

I am using netcfg to connect to my network, but I've also tried using wpa_supplicant and dhcpcd directly, which results in the same problems. One thing I forgot to mention in my original post is I tried to use ndiswrapper with the XP-64 drivers, but that resulted in a kernel panic. (and taught me a valuable lesson about verifying things work before putting them in the MODULES array...)

Last edited by akb825 (2011-05-15 02:04:26)

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#4 2011-05-15 08:12:02

akb825
Member
Registered: 2011-03-27
Posts: 81

Re: ath9k slow an unreliable; carl9170 randomly stalls

A little more information: Here's the output for iwconfig

wlan0     IEEE 802.11bgn  ESSID:"d20"  
          Mode:Managed  Frequency:2.417 GHz  Access Point: 00:18:E7:EF:EA:9E   
          Bit Rate=104 Mb/s   Tx-Power=19 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=40/70  Signal level=-70 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:64   Missed beacon:0

Despite this decent looking output for bit rate and signal, scp is currently transferring at around 60 KB/s. However, the "Invalid misc" part seems to be increasing at a fast rate when transferring data. (after around a minute of letting scp run, it had an additional 100 "Invalid misc") This seems to be similar to the kernel bug that I linked to, but it happens regardless of hardware encryption and the version of the kernel I am running already has the fix, though it's possible it's a separate bug related bug.

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#5 2011-05-15 08:35:52

litemotiv
Forum Fellow
Registered: 2008-08-01
Posts: 5,026

Re: ath9k slow an unreliable; carl9170 randomly stalls

akb825 wrote:

However, the "Invalid misc" part seems to be increasing at a fast rate when transferring data.

I don't think that is problematic, here is my current output for a card that runs without problems:

wlan0     IEEE 802.11abgn  ESSID:"Pyongyang"  
          Mode:Managed  Frequency:5.22 GHz  Access Point: E0:91:F5:CC:98:0E   
          Bit Rate=115.6 Mb/s   Tx-Power=20 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=55/70  Signal level=-55 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:2  Invalid misc:7994   Missed beacon:0

Do note that ssh/scp is very inefficient for copying files remotely.

Also, could you please change your topic title to something that actually describes the problem?


ᶘ ᵒᴥᵒᶅ

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#6 2011-05-15 09:19:51

akb825
Member
Registered: 2011-03-27
Posts: 81

Re: ath9k slow an unreliable; carl9170 randomly stalls

Thanks for the comparison for iwconfig.

Scp is not that inefficient at transferring files. IIRC I've done transfers over gigabit ethernet at about 40 MB/s, which is in the same league as copying files from one disk to another on the same computer. Also, note that my USB wireless dongle will transfer at 2.5 MB/s, even though it will cut out periodically. 60 KB/s for the D-Link card is several orders of magnitude lower than what I would expect.

I have renamed the thread per your request. (it's not quite as eye grabbing, though wink)

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