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yingqiang Ma | 1 Apr 2010 06:21
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Group Key fix for VAPs

When I set up multiple VAPs with ath9k, I encountered an issue that
the traffic may be lost after a while.

The detailed phenomenon is
1. After a while the clients connected to one of these VAPs will get
into a state that no broadcast/multicast packets can be transfered
successfully while the unicast packets can be transfered normally.
2. Minutes latter the unitcast packets transfer will fail as well,
because the ARP entry is expired and it can't be freshed due to the
broadcast trouble.

It caused by the group key overwritten and someone discussed this
issue before, but haven't work out a fix yet.

I referred the method in madwifi, and made a patch for ath9k.
The method is to set the high bit of the sender(AP)'s address, and
associated that mac and the group key. It requires the hardware
supports multicast frame key search. It seems true for AR9160.

Not sure whether it's the correct way to fix this issue. But it seems
to work in my test. The patch is attached, feel free to revise it.

Regards & Thanks,
Daniel Ma
Attachment (vap_group_key.patch): application/octet-stream, 2180 bytes
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Pavel Roskin | 2 Apr 2010 04:35
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Re: No 80211n possible with AR9220?

On Tue, 2010-03-30 at 17:29 +0200, Dennis Borgmann wrote:

> # iw dev wlan1 link
> Connected to 00:0e:8e:24:52:2f (on wlan1)
>     SSID: testsalat
>     freq: 2462
>     RX: 40496 bytes (404 packets)
>     TX: 3046 bytes (38 packets)
>     signal: -48 dBm
>     tx bitrate: 1.0 MBit/s

I tried AR9220 on the AP side and AR9280 on the station side.
Everything worked fine with 802.11n.  That's what I get on the client:

# iw dev wlan1 link
Connected to 00:26:5a:c2:4c:3d (on wlan1)
        SSID: mike2
        freq: 2462
        RX: 111244 bytes (629 packets)
        TX: 20186 bytes (176 packets)
        signal: -23 dBm
        tx bitrate: 117.0 MBit/s MCS 14

I'm using the current linux-wireless on both sides, so that may be the
reason.  I tried channels 6 and 11.  I tried no encryption and WPA2 with
CCMP.

I saw the bitrate fall to 1 Mbps if there is no traffic, but it would
immediately return to a high value once I start pinging the AP.
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Pavel Roskin | 2 Apr 2010 07:25
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Constant data modified, problem for multiple cards

Hello!

ath9k uses cast in INIT_INI_ARRAY to remove const modifier from the
tables of the initial values of registers.  The tables are actually
modified in three places:

ath9k_hw_4k_set_addac()
ath9k_hw_def_set_addac()
ath9k_hw_init_eeprom_fix()

If there are multiple devices supported by ath9k, modifications made for
one device will affect other devices.

I can actually observe the problem by using D-Link DWL-552 rev A2 and
Ubiquiti SR71-15 on the same system.  Ubiquiti SR71-15 needs adjustment
for AR_AN_TOP2 in ath9k_hw_init_eeprom_fix() (pBase->pwdclkind = 0), but
D-Link DWL-552 doesn't (pBase->pwdclkind = 1).  If both cards are
present, both will be using the values for the card that is initialized
last.

Possible fixed could be:

1) Apply fixups whenever iniAddac or iniModes are used.  The fixed
values could be precalculated and stored for the card.

2) Use a variation of INIT_INI_ARRAY that would call kmalloc().  Use it
for iniAddac and iniModes.  Free those tables when ah is freed.

The first approach is easier to implement.  There are just a few
replacement values for the card.  ath9k_hw_process_ini() already does
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Ming Lei | 5 Apr 2010 15:28
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Re: 20/40 MHz

2010/3/26 Mohammad Abdelhadi <mo.jaser <at> gmail.com>:
> Dear All,
> I want to know which file (or part) in the driver is responsible to set the
> channel bandwidth to 20 or 40 MHz? I know that (iw) command do that.
> Also, I want to know which part is responsible for the backoff algorithm and
> how the driver interact if a collision happens.
> Thank you in advance...

hostapd: src/ap/hw_features.c

--

-- 
Lei Ming
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Rakesh Kumar | 6 Apr 2010 01:11
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About A-MPDU aggregation. ATH_AMPDU_SUBFRAME_DEFAULT flag.

Hi,


I notice this parameter ATH_AMPDU_SUBFRAME_DEFAULT and in the code in xmit.c, function ath_tx_form_aggr limits the number of sub-frames that can be included in a A-MPDU to half the total size. The accompanying comments say:

                /* do not exceed subframe limit */

But why halve the baw_size for that? I looked around the standard documents, couldn't find any reference to halving the station-specfic baw_size (negotiated during association) to half.

--
Rakesh
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Felix Fietkau | 6 Apr 2010 01:40

Re: About A-MPDU aggregation. ATH_AMPDU_SUBFRAME_DEFAULT flag.

On 2010-04-05 4:11 PM, Rakesh Kumar wrote:
> Hi,
> 
> I notice this parameter ATH_AMPDU_SUBFRAME_DEFAULT and in the code in
> xmit.c, function ath_tx_form_aggr limits the number of sub-frames that
> can be included in a A-MPDU to half the total size. The accompanying
> comments say:
> 
>                 /* do not exceed subframe limit */
> 
> But why halve the baw_size for that? I looked around the standard
> documents, couldn't find any reference to halving the station-specfic
> baw_size (negotiated during association) to half.
Maybe because ath9k tries to keep two A-MPDU aggregates in the xmit
queue and has to handle retransmission of failed subframes in software.
IMHO it makes sense to use half of the BAW for each of the queue entries
under those conditions.

- Felix
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Rakesh Kumar | 6 Apr 2010 05:10
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Re: About A-MPDU aggregation. ATH_AMPDU_SUBFRAME_DEFAULT flag.


IMHO it makes sense to use half of the BAW for each of the queue entries
under those conditions.


Can you point where (which function(s)/file(s)) the two A-MPDU keeping logic is implemented?

Thanks.

--
Rakesh
 

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Eric | 6 Apr 2010 08:51

Question about Dlink DWA-556 and rhel 5.5 x86 64 kernel 2.6.18-194.el5

I have a Dlink DWA-556 which works great under Windows 7 64 , but under
rhel 5.4,
no go.  There wasn't any 64 bit support for NDIS or any support in
madwifi.

I just upgraded to rhel 5.5.  In 5.5, at least I see a wlan0 /dev.  If I
try to configure it with the gui tool or the iw cmd line tools, it does
everything except get an IP address and it times out.

Linux kernel version 2.6.18-194.el5

Here are some details:

dmesg:

ath: EEPROM regdomain: 0x10
ath: EEPROM indicates we should expect a direct regpair map
ath: Country alpha2 being used: CO
ath: Regpair used: 0x10
GSI 23 sharing vector 0x4A and IRQ 23
ACPI: PCI Interrupt 0000:00:1b.0[A] -> GSI 22 (level, low) -> IRQ 74
PCI: Setting latency timer of device 0000:00:1b.0 to 64
hda_codec: ALC888: BIOS auto-probing.
phy0: Selected rate control algorithm 'ath9k_rate_control'
cfg80211: Calling CRDA for country: CO
cfg80211: Regulatory domain changed to country: CO
        (start_freq - end_freq  <at>  bandwidth), (max_antenna_gain, max_eirp)
        (2402000 KHz - 2472000 KHz  <at>  40000 KHz), (300 mBi, 2700 mBm)
        (5170000 KHz - 5250000 KHz  <at>  20000 KHz), (300 mBi, 1700 mBm)
        (5250000 KHz - 5330000 KHz  <at>  20000 KHz), (300 mBi, 2300 mBm)
        (5735000 KHz - 5835000 KHz  <at>  20000 KHz), (300 mBi, 3000 mBm)
Registered led device: ath9k-phy0::radio
Registered led device: ath9k-phy0::assoc
Registered led device: ath9k-phy0::tx
Registered led device: ath9k-phy0::rx
phy0: Atheros AR5418 MAC/BB Rev:2 AR2133 RF Rev:81:
mem=0xffffc20000040000, irq=169
ADDRCONF(NETDEV_UP): wlan0: link is not ready

lspci:

03:00.0 Network controller: Atheros Communications Inc. AR5008 Wireless
Network Adapter (rev 01)

The iwconfig:

wlan0     IEEE 802.11bgn  ESSID:"levinsong"
          Mode:Managed  Frequency:2.462 GHz  Access Point: 00:22:75:62:3D:B0
          Bit Rate=54 Mb/s   Tx-Power=27 dBm
          RTS thr:off   Fragment thr:off
          Encryption key:33B8-BBF2-BD
          Power Management:off
          Link Quality=61/70  Signal level=-49 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

Any help would be greatly appreciated.

Eric
eric <at> levinsong.com
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Zhang Yanfei-B21500 | 6 Apr 2010 09:34
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Re: 80.11n Performance Tunning

Hi Sivakumar
 
    Do you have some result abou the 11n performance tunning? or anyone else have got a good result? Now i am testing the ar9160 11n performance, and found in 2.4Ghz is not stable, the link speed is 1Mbps sometimes. but in 5Ghz, it's good at 270Mbps or 300Mbps.
 
 
 
Best Regards,
Yanfei Zhang
 

From: ath9k-devel-bounces <at> venema.h4ckr.net [mailto:ath9k-devel-bounces <at> venema.h4ckr.net] On Behalf Of Sivakumar Mohan
Sent: Wednesday, January 27, 2010 6:33 PM
To: Lorenzo Bianconi
Cc: ath9k-devel <at> lists.ath9k.org
Subject: Re: [ath9k-devel] 80.11n Performance Tunning

Hi Lorenzo
 
Thank you for your advice. I  am using a IKANOS properitery board with atheros Chipset (). I would like to know how the antennas are to be configured ?  Googling around showed me certain params like ht-extension-channel, ht-rxchains, ht-txchains and mcs.  Are these handled in ath9k ?
 
Thanks
 
 

Sivakumar Mohan,

Aricent Technologies (Holdings) Ltd.,

RR 4 Tower, 6th Floor,

Thiruvika Industrial Estate, Guindy, Chennai - 600032

TamilNadu India.

PH: +91 44 4422 5543

 

 

 

From: Lorenzo Bianconi [mailto:lorenzo.bianconi83 <at> gmail.com]
Sent: Monday, January 25, 2010 9:50 PM
To: Sivakumar Mohan
Cc: ath9k-devel <at> lists.ath9k.org
Subject: Re: [ath9k-devel] 80.11n Performance Tunning



2010/1/25 Sivakumar Mohan <sivakumar.mohan <at> aricent.com>
Hi all !
 
          I am new to 802.11n. Please let me know what are the performance tunning parameters that I can use for tuning my 11n Ap. Would this be able to be done using the traditional
iwconfig like wireless extension toolkit. What setting should I give for a card with 3x3 antenna with the diversity ?
 
 
Thanks
 

Sivakumar Mohan,

Aricent Technologies (Holdings) Ltd.,

RR 4 Tower, 6th Floor,

Thiruvika Industrial Estate, Guindy, Chennai - 600032

TamilNadu India.

PH: +91 44 4422 5543

 

 

 

"DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."

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Hi Sivakumar,

    you has just to set the frequency and channel width through iw utility (i.e. iw dev wlan0 set channel 36 HT40+)
in order to maximize the link throughput. 
What kind of wireless device are you using? what is the maximum throughput you currently achieve?

Regards,

Lorenzo

"DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."
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Eric Levinson | 6 Apr 2010 09:46

Re: Question about Dlink DWA-556 and rhel 5.5 x86 64 kernel 2.6.18-194.el5

Thanks, yea, I noticed this is a development list after I posted, sorry!

-----Original Message-----
From: Alan [mailto:lameventanas <at> gmail.com] 
Sent: Tuesday, April 06, 2010 12:44 AM
To: eric <at> levinsong.com
Subject: Re: [ath9k-devel] Question about Dlink DWA-556 and rhel 5.5 x86 64 kernel 2.6.18-194.el5

Dude, you are asking such a newbie question in a mailing list that is
supposed to be for kernel development, this is not the right place to
ask.  A better place would be an irc channel, or your distro's mailing
list.

Besides all that, you don't even provide enough information.
What you are trying to do?  I'll assume you are just trying to set
your network card in managed mode, and then connect using an access
point.
Are you are trying to use WEP, WPA, WPA2?
Just read the man-pages of iwconfig and wpa_supplicant, or look for
these terms in a search engine.
I'm sure you will find the answer in 5 minutes if you just look for it.

On Tue, Apr 6, 2010 at 3:51 PM, Eric <eric <at> levinsong.com> wrote:
> I have a Dlink DWA-556 which works great under Windows 7 64 , but under
> rhel 5.4,
> no go.  There wasn't any 64 bit support for NDIS or any support in
> madwifi.
>
> I just upgraded to rhel 5.5.  In 5.5, at least I see a wlan0 /dev.  If I
> try to configure it with the gui tool or the iw cmd line tools, it does
> everything except get an IP address and it times out.
>
> Linux kernel version 2.6.18-194.el5
>
>
>
> Here are some details:
>
> dmesg:
>
> ath: EEPROM regdomain: 0x10
> ath: EEPROM indicates we should expect a direct regpair map
> ath: Country alpha2 being used: CO
> ath: Regpair used: 0x10
> GSI 23 sharing vector 0x4A and IRQ 23
> ACPI: PCI Interrupt 0000:00:1b.0[A] -> GSI 22 (level, low) -> IRQ 74
> PCI: Setting latency timer of device 0000:00:1b.0 to 64
> hda_codec: ALC888: BIOS auto-probing.
> phy0: Selected rate control algorithm 'ath9k_rate_control'
> cfg80211: Calling CRDA for country: CO
> cfg80211: Regulatory domain changed to country: CO
>        (start_freq - end_freq  <at>  bandwidth), (max_antenna_gain, max_eirp)
>        (2402000 KHz - 2472000 KHz  <at>  40000 KHz), (300 mBi, 2700 mBm)
>        (5170000 KHz - 5250000 KHz  <at>  20000 KHz), (300 mBi, 1700 mBm)
>        (5250000 KHz - 5330000 KHz  <at>  20000 KHz), (300 mBi, 2300 mBm)
>        (5735000 KHz - 5835000 KHz  <at>  20000 KHz), (300 mBi, 3000 mBm)
> Registered led device: ath9k-phy0::radio
> Registered led device: ath9k-phy0::assoc
> Registered led device: ath9k-phy0::tx
> Registered led device: ath9k-phy0::rx
> phy0: Atheros AR5418 MAC/BB Rev:2 AR2133 RF Rev:81:
> mem=0xffffc20000040000, irq=169
> ADDRCONF(NETDEV_UP): wlan0: link is not ready
>
>
> lspci:
>
> 03:00.0 Network controller: Atheros Communications Inc. AR5008 Wireless
> Network Adapter (rev 01)
>
> The iwconfig:
>
> wlan0     IEEE 802.11bgn  ESSID:"levinsong"
>          Mode:Managed  Frequency:2.462 GHz  Access Point: 00:22:75:62:3D:B0
>          Bit Rate=54 Mb/s   Tx-Power=27 dBm
>          RTS thr:off   Fragment thr:off
>          Encryption key:33B8-BBF2-BD
>          Power Management:off
>          Link Quality=61/70  Signal level=-49 dBm
>          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
>          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
>
> Any help would be greatly appreciated.
>
> Eric
> eric <at> levinsong.com
>
>
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel <at> lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
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