Re: Issue with ath9k and tx/rx chainmask: 3x3 doesn't work with mask of 0x1.

[Ben Greear <greearb@candelatech.com>]

On 08/22/2012 05:05 PM, Ben Greear wrote:
> On 08/22/2012 03:24 PM, Ben Greear wrote:
>> On 08/22/2012 01:30 PM, Felix Fietkau wrote:
>>> On 2012-08-20 10:24 PM, Ben Greear wrote:
>>>> I am trying to test out an attenuator.  For now, I have only a single attenuator,
>>>> so I set tx and rx chainmask to 0x1 on both AP and Station machine.
>>>>
>>>> I then connected channel 0 on the two machines together through the
>>>> attenuator.
>>>>
>>>> I have two station interfaces on the station machine.  They both
>>>> seem to associate OK, but they cannot receive dhcp responses.
>>>>
>>>> It *seems* that broadcast packets may go through fine.
>>>>
>>>> If I force the rate down to 1x1 or 2x2 MIMO (or force disable /n
>>>> and just use /a), then it appears to work fine.
>>>>
>>>> Nics are WPEA-127n (AR9380).  Kernel is 3.5.1+ on AP, 3.5.2+ on station
>>>> machine.
>>>>
>>>> I can see why forcing it down to 1x1 might work around some issue,
>>>> but I find it funny that 2x2 works while 3x3 does not.
>>> Did you set the chainmask manually via debugfs? If so, don't do that!
>>> Use the nl80211 antenna control API (e.g. via iw)
>>
>> [root@lec2010-ath9k-1 lanforge]# ./local/sbin/iw phy wiphy0 set antenna 1 1
>> command failed: Operation not supported (-95)
>> [root@lec2010-ath9k-1 lanforge]# ./local/sbin/iw phy wiphy0 set antenna 1
>> command failed: Operation not supported (-95)
>> [root@lec2010-ath9k-1 lanforge]# ./local/sbin/iw phy wiphy0 set antenna 3
>> command failed: Operation not supported (-95)
>> [root@lec2010-ath9k-1 lanforge]# ./local/sbin/iw phy wiphy0 set antenna 7
>> command failed: Operation not supported (-95)
>> [root@lec2010-ath9k-1 lanforge]# uname -a
>> Linux lec2010-ath9k-1 3.5.1+ #15 SMP PREEMPT Thu Aug 9 09:31:45 PDT 2012 i686 i686 i386 GNU/Linux
>
> I'm guessing it is because of this:
>
> static int ieee80211_set_antenna(struct wiphy *wiphy, u32 tx_ant, u32 rx_ant)
> {
>      struct ieee80211_local *local = wiphy_priv(wiphy);
>
>      if (local->started)
>          return -EOPNOTSUPP;
>
>      return drv_set_antenna(local, tx_ant, rx_ant);
> }

Even when I manually admin down everything, I can still freeze the NIC
(WPEA-127n, AR9380).

To reproduce:
stop all VAP/STA interfaces on wiphy0
set tx and rx chainmask to 2 using 'iw'
start vap0

# Boom, fails to reset, and for whatever reason, local->started never
# goes false, so you can't even set the chainmask back using 'iw'.


Aug 22 17:41:34 localhost dhcpd: DHCPDISCOVER from 00:00:08:76:52:14 via rddVR17: network 99.88.77.0/24: no free leases
Aug 22 17:41:37 localhost kernel: [ 5575.474706] ath: wiphy0: Unable to reset hardware; reset status -5 (freq 5785 MHz)
Aug 22 17:41:38 localhost kernel: [ 5576.116434] ath: wiphy0: Unable to reset hardware; reset status -5 (freq 5785 MHz)
Aug 22 17:41:38 localhost kernel: [ 5576.476336] ath: wiphy0: Unable to reset hardware; reset status -5 (freq 5785 MHz)
Aug 22 17:41:45 localhost kernel: [ 5582.653715] ath: wiphy0: Unable to reset hardware; reset status -5 (freq 5785 MHz)
Aug 22 17:41:46 localhost dhclient[18218]: DHCPDISCOVER on rddVR18 to 255.255.255.255 port 67 interval 11
Aug 22 17:41:46 localhost dhcpd: DHCPDISCOVER from 26:0c:f3:49:95:16 via rddVR17: network 99.88.77.0/24: no free leases
Aug 22 17:41:47 localhost dhclient[18706]: DHCPDISCOVER on rddVR18#4 to 255.255.255.255 port 67 interval 14
Aug 22 17:41:47 localhost dhcpd: DHCPDISCOVER from 00:00:08:76:52:14 via rddVR17: network 99.88.77.0/24: no free leases
Aug 22 17:41:57 localhost dhclient[18218]: DHCPDISCOVER on rddVR18 to 255.255.255.255 port 67 interval 7
Aug 22 17:41:57 localhost dhcpd: DHCPDISCOVER from 26:0c:f3:49:95:16 via rddVR17: network 99.88.77.0/24: no free leases
Aug 22 17:41:59 localhost kernel: [ 5597.279989] in set_wiphy
Aug 22 17:41:59 localhost kernel: [ 5597.296604] in set_wiphy
Aug 22 17:41:59 localhost kernel: [ 5597.314646] in set_wiphy
Aug 22 17:41:59 localhost kernel: [ 5597.319479] set antenna failed, local->started
Aug 22 17:41:59 localhost kernel: [ 5597.326555] ops->set_antenna rv: -95



Thanks,
Ben


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com