2009-01-05 17:04:36

by Luis R. Rodriguez

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.2{7, 8} with compat-wireless-2008-12-3{0, 1) drops link every 2-3 minutes

On Wed, Dec 31, 2008 at 11:52:32PM -0800, Joseph Cheek wrote:
> Hi all,
>
> Happy New Year! It's about 2:30 AM here and I'm up debugging my shiny
> new DWA-552 <AR5416+AR2133> XtremeN Desktop Adapter. Stock 2.6.28 gave
> me the dreaded "No ProbeResp from current AP" in syslog with a
> disconnect every few minutes, even after updating
> |IEEE80211_MONITORING_INTERVAL to (100 * HZ). It's highly annoying.

This should be due to the fact that the RX filter disabled beaconing from
the current AP and mac80211 expects beacons from the AP. This was fixed
in wireless-testing but I do not see this pushed out for 2.6.28.

Greg, this was fixed in Linus' tree via ffb826767bffda61426d964a8fc24a216a14b0bd,
merged by John on Fri, 21 Nov 2008, the patch is titled:
"ath9k: enable RXing of beacons on STA/IBSS". Just in case I've
provided the hunk below. Without this patch users will face this disconnect
issue on noisy environments where the beacons don't reach mac80211 within
a certain time frame dicated by mac80211.

> I thought compat-wireless might help.

It should resolve the "No ProbeResp from current AP" in" issue at least.

> It seems to do a little bit better
> but that's subjective. I still get a disconnect every few minutes.
> iwconfig and my DIR-655 show plenty of signal strength but it doesn't
> respond to pings and my ssh sessions all get stuck in limbo.
>
> What can I do to debug this? This is an old Athlon XP 2000+ box running
> Gentoo (if it helps). I've seen a few other probs on this list recently
> but they don't seem similar to mine enough to warrant tacking this msg
> on to an existing thread.

That may be due to a separate issue, but to review that we need more information,
such as the type of AP you are connecting to, encryption options used, mode
of operation (11n, 11b or 11a), your type of environment (noisy or a quiet home).
To review this issue you can remove [email protected] from the To or Cc list.

Luis

--- drivers/net/wireless/ath9k/recv.c.orig 2009-01-05 08:44:45.000000000 -0800
+++ drivers/net/wireless/ath9k/recv.c 2009-01-05 08:46:40.000000000 -0800
@@ -627,9 +627,8 @@
rfilt &= ~ATH9K_RX_FILTER_UCAST;
}

- if (((sc->sc_ah->ah_opmode == ATH9K_M_STA) &&
- (sc->rx_filter & FIF_BCN_PRBRESP_PROMISC)) ||
- (sc->sc_ah->ah_opmode == ATH9K_M_IBSS))
+ if (sc->sc_ah->ah_opmode == ATH9K_M_STA ||
+ sc->sc_ah->ah_opmode == ATH9K_M_IBSS)
rfilt |= ATH9K_RX_FILTER_BEACON;

/* If in HOSTAP mode, want to enable reception of PSPOLL frames


2009-01-05 18:12:54

by Luis R. Rodriguez

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 minutes

On Mon, Jan 05, 2009 at 10:01:52AM -0800, Joseph Cheek wrote:
> Thanks Luis! Comments below...
>
> Luis R. Rodriguez wrote:
> > On Wed, Dec 31, 2008 at 11:52:32PM -0800, Joseph Cheek wrote:
> >
> >> Hi all,
> >>
> >> Happy New Year! It's about 2:30 AM here and I'm up debugging my shiny
> >> new DWA-552 <AR5416+AR2133> XtremeN Desktop Adapter. Stock 2.6.28 gave
> >> me the dreaded "No ProbeResp from current AP" in syslog with a
> >> disconnect every few minutes, even after updating
> >> |IEEE80211_MONITORING_INTERVAL to (100 * HZ). It's highly annoying.
> >>
> >
> > This should be due to the fact that the RX filter disabled beaconing from
> > the current AP and mac80211 expects beacons from the AP. This was fixed
> > in wireless-testing but I do not see this pushed out for 2.6.28.
> >
> > Greg, this was fixed in Linus' tree via ffb826767bffda61426d964a8fc24a216a14b0bd,
> > merged by John on Fri, 21 Nov 2008, the patch is titled:
> > "ath9k: enable RXing of beacons on STA/IBSS". Just in case I've
> > provided the hunk below. Without this patch users will face this disconnect
> > issue on noisy environments where the beacons don't reach mac80211 within
> > a certain time frame dicated by mac80211.
> >
> >
> >> I thought compat-wireless might help.
> >>
> >
> > It should resolve the "No ProbeResp from current AP" in" issue at least.
> >
>
> I haven't been getting that message in syslog recently (since the 2nd).
> I moved back to 2.6.27 with compat-wireless-12-31 as that seems the most
> stable with the highest speeds. I also specified the AP on the iwconfig
> command line, thinking that perhaps that would help.
> >> It seems to do a little bit better
> >> but that's subjective. I still get a disconnect every few minutes.
> >> iwconfig and my DIR-655 show plenty of signal strength but it doesn't
> >> respond to pings and my ssh sessions all get stuck in limbo.
> >>
> >> What can I do to debug this? This is an old Athlon XP 2000+ box running
> >> Gentoo (if it helps). I've seen a few other probs on this list recently
> >> but they don't seem similar to mine enough to warrant tacking this msg
> >> on to an existing thread.
> >>
> >
> > That may be due to a separate issue, but to review that we need more information,
> > such as the type of AP you are connecting to, encryption options used, mode
> > of operation (11n, 11b or 11a), your type of environment (noisy or a quiet home).
> > To review this issue you can remove [email protected] from the To or Cc list.
> >
>
> based on my recent observations, I believe you are correct - this is a
> separate issue. I no longer get the noProbeResp error but I still get
> transmission problems every 2 minutes or so under heavy loads. They
> don't result in actual disconnects - ifconfig shows the interface up and
> iwconfig shows it connected to the AP. So the link is no longer being
> dropped. But for about 30 seconds, I can neither ping nor ssh in or out
> of that box. If leave the system up and don't cancel anything, the
> transmission resumes after the 30 seconds and then stalls again after 2
> minutes or so.
>
> My AP is a D-Link DIR-655 running 1.21 firmware in g/n mode. No
> encryption is enabled currently (I do have MAC filtering on, but nothing
> else). The particular box with the problem is downstairs and there is
> some interference between it and AP, although the DIR-655 generally
> shows 60-80% signal and up to 81Mb/s connection speed. It doesn't
> happen with light traffic, I have to be watching a streaming video or
> scp-ing a file across the network. Then it is 100% repeatable.
>
> If I restart the network (/etc/init.d/wlan0 restart) I can get a good
> connection/signal with good traffic without having to wait 30 seconds -
> for two minutes again 8-(.
>
> This is at home and most of my neighbors have 80211g wireless set up. I
> generally see at least two other APs from iwlist wlan0 scanning. I
> haven't pinned either the AP or the NIC to a channel (6 is normal for US
> but they are connecting on 3). Not sure if that makes a difference.
>
> My laptop right next to the AP has no problems staying connected and
> transmitting and receiving with stock 2.6.27. It's running a DWL-652
> (AR5416).
>
> btw, when i do get good transmission, I only get about 1.25MB/s at the
> most. I can get that from my old g card 8-(.

Thanks for the details, this seems to be related to noise and therefore
could be due to some issues with how we deal with ANI. We will have to
try to reproduce this ourselves now and try to fix it.

> I can try anything you need me to with respect to ath9k drivers or
> kernels. does it matter if bluetooth and/or ipv6 is enabled? both are
> enabled on this box but not on my laptop?

Anything communication on the same spectrum affects your 802.11 connection,
so using the microwave oven, using bluetooth, or a 2.4 GHz home phone should
affet your connection. Not sure the freq used by Xbox / PS3 controllers...
Bluetooth particularly should affect your 802.11 connection and we only recently
added bluetooth coexistance to help with this but this is only available for
more modern cards so your card does not have this feature.

If you are using bluetooth then it should affect your connection if using the
2.4 GHz spectrum on your wirless AP.

Luis

2009-01-15 19:03:24

by Greg KH

[permalink] [raw]
Subject: Re: [stable] [ath9k-devel] 2.6.2{7, 8} with compat-wireless-2008-12-3{0, 1) drops link every 2-3 minutes

On Mon, Jan 05, 2009 at 09:04:32AM -0800, Luis R. Rodriguez wrote:
> On Wed, Dec 31, 2008 at 11:52:32PM -0800, Joseph Cheek wrote:
> > Hi all,
> >
> > Happy New Year! It's about 2:30 AM here and I'm up debugging my shiny
> > new DWA-552 <AR5416+AR2133> XtremeN Desktop Adapter. Stock 2.6.28 gave
> > me the dreaded "No ProbeResp from current AP" in syslog with a
> > disconnect every few minutes, even after updating
> > |IEEE80211_MONITORING_INTERVAL to (100 * HZ). It's highly annoying.
>
> This should be due to the fact that the RX filter disabled beaconing from
> the current AP and mac80211 expects beacons from the AP. This was fixed
> in wireless-testing but I do not see this pushed out for 2.6.28.
>
> Greg, this was fixed in Linus' tree via ffb826767bffda61426d964a8fc24a216a14b0bd,
> merged by John on Fri, 21 Nov 2008, the patch is titled:
> "ath9k: enable RXing of beacons on STA/IBSS". Just in case I've
> provided the hunk below. Without this patch users will face this disconnect
> issue on noisy environments where the beacons don't reach mac80211 within
> a certain time frame dicated by mac80211.

Thanks, I'll queue this up for 2.6.28, but it doesn't apply to
2.6.27-stable. If you want it there, can you please provide a backport
for it?

thanks,

greg k-h

2009-01-05 20:15:12

by Luis R. Rodriguez

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 minutes

On Mon, Jan 05, 2009 at 11:51:24AM -0800, Luis Rodriguez wrote:
> On Mon, Jan 05, 2009 at 11:47:08AM -0800, Joseph Cheek wrote:
> > Is this page up to date? I found the latest 802.11n NIC that I could
> > find for my machine...
> >
> > http://wireless.kernel.org/en/users/Drivers/ath9k#ProductsintheretailmarketcontainingAtheros11nsolutions
> >
> > I bought my card after specifically consulting this page.
>
> Yes.

Just FYI the Bluetooth coexistance stuff seems to be a feature of at least
AR9280 revision 10 and later so if you have an older card than you don't have
BT coexistance, at least from what I can tell.

Luis

2009-01-06 15:42:09

by Joseph Cheek

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 minutes

Hi,

looks like i misspoke. my laptop, this morning, lost its connection for
about 30 seconds while running a remote X app. I just sshed to another
box (running a g card with a broadcom chipset 8-), exported the display
back to my laptop, and started ripperX. About 2/3 into the rip the
connection stalled for about 30 seconds and then came back. perhaps i
didn't see it before because i don't do any video serving from my
laptop? unsure. i do watch the videos there, and i would expect the
bandwidth utilization to be the same. at least it seems bandwidth related.

speaking of the broadcom card, it reassociated with the access point
automatically after a reboot (of the access point). both d-link/atheros
cards needed some work to get it to reassociate - the desktop needed a
reboot and the laptop needed a reinsertion of the pcmcia card. possibly
rmmod/modprobe ath9k would have worked to get it to reassociate, but
/etc/init.d/net.wlan0 restart did not work.

thanks for your help!

Joseph Cheek

Joseph Cheek wrote:
> My laptop right next to the AP has no problems staying connected and
> transmitting and receiving with stock 2.6.27. It's running a DWL-652
> (AR5416).
>

2009-01-05 20:01:25

by Joseph Cheek

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 mins

thanks, Luis! comments below...

Luis R. Rodriguez wrote:
> Thanks for the details, this seems to be related to noise and therefore
> could be due to some issues with how we deal with ANI. We will have to
> try to reproduce this ourselves now and try to fix it.
>

great! i wish you luck! would it help it i try the same test with the
problematic box right next to the AP? I could move it upstairs to the
same room and retry an SCP or video serve. not sure if that would give
you more useful data or not, but i can certainly move it.

if the box were quiet enough, i would keep it in the same room and just
connect via ethernet 8-).

>> I can try anything you need me to with respect to ath9k drivers or
>> kernels. does it matter if bluetooth and/or ipv6 is enabled? both are
>> enabled on this box but not on my laptop?
>>
>
> Anything communication on the same spectrum affects your 802.11 connection,
> so using the microwave oven, using bluetooth, or a 2.4 GHz home phone should
> affet your connection. Not sure the freq used by Xbox / PS3 controllers...
> Bluetooth particularly should affect your 802.11 connection and we only recently
> added bluetooth coexistance to help with this but this is only available for
> more modern cards so your card does not have this feature.
>
> If you are using bluetooth then it should affect your connection if using the
> 2.4 GHz spectrum on your wirless AP.
>

I didn't actually have the bluetooth in use, just the module built. so
that might not be the problem. the DIR-655 will do 5MHz only if it's in
n-only mode, and I have too many g devices in the house to want to
replace them all 8-).

> Luis
>

2009-01-05 19:51:28

by Luis R. Rodriguez

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 minutes

On Mon, Jan 05, 2009 at 11:47:08AM -0800, Joseph Cheek wrote:
> Is this page up to date? I found the latest 802.11n NIC that I could
> find for my machine...
>
> http://wireless.kernel.org/en/users/Drivers/ath9k#ProductsintheretailmarketcontainingAtheros11nsolutions
>
> I bought my card after specifically consulting this page.

Yes.

Luis

2009-01-05 19:47:02

by Joseph Cheek

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 minutes

Is this page up to date? I found the latest 802.11n NIC that I could
find for my machine...

http://wireless.kernel.org/en/users/Drivers/ath9k#ProductsintheretailmarketcontainingAtheros11nsolutions

I bought my card after specifically consulting this page.

thanks!

Joseph Cheek

Luis R. Rodriguez wrote:
> Anything communication on the same spectrum affects your 802.11
> connection,
> so using the microwave oven, using bluetooth, or a 2.4 GHz home phone should
> affet your connection. Not sure the freq used by Xbox / PS3 controllers...
> Bluetooth particularly should affect your 802.11 connection and we only recently
> added bluetooth coexistance to help with this but this is only available for
> more modern cards so your card does not have this feature.
>
> If you are using bluetooth then it should affect your connection if using the
> 2.4 GHz spectrum on your wirless AP.
>
> Luis
>
>

2009-01-05 18:01:47

by Joseph Cheek

[permalink] [raw]
Subject: Re: [ath9k-devel] 2.6.27 with compat-wireless-2008-12-31 stops transmitting every 2-3 minutes

Thanks Luis! Comments below...

Luis R. Rodriguez wrote:
> On Wed, Dec 31, 2008 at 11:52:32PM -0800, Joseph Cheek wrote:
>
>> Hi all,
>>
>> Happy New Year! It's about 2:30 AM here and I'm up debugging my shiny
>> new DWA-552 <AR5416+AR2133> XtremeN Desktop Adapter. Stock 2.6.28 gave
>> me the dreaded "No ProbeResp from current AP" in syslog with a
>> disconnect every few minutes, even after updating
>> |IEEE80211_MONITORING_INTERVAL to (100 * HZ). It's highly annoying.
>>
>
> This should be due to the fact that the RX filter disabled beaconing from
> the current AP and mac80211 expects beacons from the AP. This was fixed
> in wireless-testing but I do not see this pushed out for 2.6.28.
>
> Greg, this was fixed in Linus' tree via ffb826767bffda61426d964a8fc24a216a14b0bd,
> merged by John on Fri, 21 Nov 2008, the patch is titled:
> "ath9k: enable RXing of beacons on STA/IBSS". Just in case I've
> provided the hunk below. Without this patch users will face this disconnect
> issue on noisy environments where the beacons don't reach mac80211 within
> a certain time frame dicated by mac80211.
>
>
>> I thought compat-wireless might help.
>>
>
> It should resolve the "No ProbeResp from current AP" in" issue at least.
>

I haven't been getting that message in syslog recently (since the 2nd).
I moved back to 2.6.27 with compat-wireless-12-31 as that seems the most
stable with the highest speeds. I also specified the AP on the iwconfig
command line, thinking that perhaps that would help.
>> It seems to do a little bit better
>> but that's subjective. I still get a disconnect every few minutes.
>> iwconfig and my DIR-655 show plenty of signal strength but it doesn't
>> respond to pings and my ssh sessions all get stuck in limbo.
>>
>> What can I do to debug this? This is an old Athlon XP 2000+ box running
>> Gentoo (if it helps). I've seen a few other probs on this list recently
>> but they don't seem similar to mine enough to warrant tacking this msg
>> on to an existing thread.
>>
>
> That may be due to a separate issue, but to review that we need more information,
> such as the type of AP you are connecting to, encryption options used, mode
> of operation (11n, 11b or 11a), your type of environment (noisy or a quiet home).
> To review this issue you can remove [email protected] from the To or Cc list.
>

based on my recent observations, I believe you are correct - this is a
separate issue. I no longer get the noProbeResp error but I still get
transmission problems every 2 minutes or so under heavy loads. They
don't result in actual disconnects - ifconfig shows the interface up and
iwconfig shows it connected to the AP. So the link is no longer being
dropped. But for about 30 seconds, I can neither ping nor ssh in or out
of that box. If leave the system up and don't cancel anything, the
transmission resumes after the 30 seconds and then stalls again after 2
minutes or so.

My AP is a D-Link DIR-655 running 1.21 firmware in g/n mode. No
encryption is enabled currently (I do have MAC filtering on, but nothing
else). The particular box with the problem is downstairs and there is
some interference between it and AP, although the DIR-655 generally
shows 60-80% signal and up to 81Mb/s connection speed. It doesn't
happen with light traffic, I have to be watching a streaming video or
scp-ing a file across the network. Then it is 100% repeatable.

If I restart the network (/etc/init.d/wlan0 restart) I can get a good
connection/signal with good traffic without having to wait 30 seconds -
for two minutes again 8-(.

This is at home and most of my neighbors have 80211g wireless set up. I
generally see at least two other APs from iwlist wlan0 scanning. I
haven't pinned either the AP or the NIC to a channel (6 is normal for US
but they are connecting on 3). Not sure if that makes a difference.

My laptop right next to the AP has no problems staying connected and
transmitting and receiving with stock 2.6.27. It's running a DWL-652
(AR5416).

btw, when i do get good transmission, I only get about 1.25MB/s at the
most. I can get that from my old g card 8-(.

I can try anything you need me to with respect to ath9k drivers or
kernels. does it matter if bluetooth and/or ipv6 is enabled? both are
enabled on this box but not on my laptop?

thanks!

Joseph Cheek

> Luis
>
> --- drivers/net/wireless/ath9k/recv.c.orig 2009-01-05 08:44:45.000000000 -0800
> +++ drivers/net/wireless/ath9k/recv.c 2009-01-05 08:46:40.000000000 -0800
> @@ -627,9 +627,8 @@
> rfilt &= ~ATH9K_RX_FILTER_UCAST;
> }
>
> - if (((sc->sc_ah->ah_opmode == ATH9K_M_STA) &&
> - (sc->rx_filter & FIF_BCN_PRBRESP_PROMISC)) ||
> - (sc->sc_ah->ah_opmode == ATH9K_M_IBSS))
> + if (sc->sc_ah->ah_opmode == ATH9K_M_STA ||
> + sc->sc_ah->ah_opmode == ATH9K_M_IBSS)
> rfilt |= ATH9K_RX_FILTER_BEACON;
>
> /* If in HOSTAP mode, want to enable reception of PSPOLL frames
>
>

2009-01-15 21:05:04

by Greg KH

[permalink] [raw]
Subject: Re: [stable] [ath9k-devel] 2.6.2{7, 8} with compat-wireless-2008-12-3{0, 1) drops link every 2-3 minutes

On Thu, Jan 15, 2009 at 12:25:50PM -0800, Luis R. Rodriguez wrote:
> On Thu, Jan 15, 2009 at 10:37:03AM -0800, Greg KH wrote:
> > On Mon, Jan 05, 2009 at 09:04:32AM -0800, Luis R. Rodriguez wrote:
> > > On Wed, Dec 31, 2008 at 11:52:32PM -0800, Joseph Cheek wrote:
> > > > Hi all,
> > > >
> > > > Happy New Year! It's about 2:30 AM here and I'm up debugging my shiny
> > > > new DWA-552 <AR5416+AR2133> XtremeN Desktop Adapter. Stock 2.6.28 gave
> > > > me the dreaded "No ProbeResp from current AP" in syslog with a
> > > > disconnect every few minutes, even after updating
> > > > |IEEE80211_MONITORING_INTERVAL to (100 * HZ). It's highly annoying.
> > >
> > > This should be due to the fact that the RX filter disabled beaconing from
> > > the current AP and mac80211 expects beacons from the AP. This was fixed
> > > in wireless-testing but I do not see this pushed out for 2.6.28.
> > >
> > > Greg, this was fixed in Linus' tree via ffb826767bffda61426d964a8fc24a216a14b0bd,
> > > merged by John on Fri, 21 Nov 2008, the patch is titled:
> > > "ath9k: enable RXing of beacons on STA/IBSS". Just in case I've
> > > provided the hunk below. Without this patch users will face this disconnect
> > > issue on noisy environments where the beacons don't reach mac80211 within
> > > a certain time frame dicated by mac80211.
> >
> > Thanks, I'll queue this up for 2.6.28, but it doesn't apply to
> > 2.6.27-stable. If you want it there, can you please provide a backport
> > for it?
>
> Thanks Greg -- it seems this was actually present in 2.6.27 since the
> initial commit of ath9k. From the initial commit I see:
>
> --- on ath_calcrxfilter()
> if (sc->sc_opmode == ATH9K_M_STA || sc->sc_opmode == ATH9K_M_IBSS ||
> sc->sc_scanning)
> rfilt |= ATH9K_RX_FILTER_BEACON;
> ---
>
> Seems we're good on 27 for this and this actually turned out to be a regression then.

Thanks for confirming it,

greg k-h

2009-01-15 20:26:19

by Luis R. Rodriguez

[permalink] [raw]
Subject: Re: [stable] [ath9k-devel] 2.6.2{7, 8} with compat-wireless-2008-12-3{0, 1) drops link every 2-3 minutes

On Thu, Jan 15, 2009 at 10:37:03AM -0800, Greg KH wrote:
> On Mon, Jan 05, 2009 at 09:04:32AM -0800, Luis R. Rodriguez wrote:
> > On Wed, Dec 31, 2008 at 11:52:32PM -0800, Joseph Cheek wrote:
> > > Hi all,
> > >
> > > Happy New Year! It's about 2:30 AM here and I'm up debugging my shiny
> > > new DWA-552 <AR5416+AR2133> XtremeN Desktop Adapter. Stock 2.6.28 gave
> > > me the dreaded "No ProbeResp from current AP" in syslog with a
> > > disconnect every few minutes, even after updating
> > > |IEEE80211_MONITORING_INTERVAL to (100 * HZ). It's highly annoying.
> >
> > This should be due to the fact that the RX filter disabled beaconing from
> > the current AP and mac80211 expects beacons from the AP. This was fixed
> > in wireless-testing but I do not see this pushed out for 2.6.28.
> >
> > Greg, this was fixed in Linus' tree via ffb826767bffda61426d964a8fc24a216a14b0bd,
> > merged by John on Fri, 21 Nov 2008, the patch is titled:
> > "ath9k: enable RXing of beacons on STA/IBSS". Just in case I've
> > provided the hunk below. Without this patch users will face this disconnect
> > issue on noisy environments where the beacons don't reach mac80211 within
> > a certain time frame dicated by mac80211.
>
> Thanks, I'll queue this up for 2.6.28, but it doesn't apply to
> 2.6.27-stable. If you want it there, can you please provide a backport
> for it?

Thanks Greg -- it seems this was actually present in 2.6.27 since the
initial commit of ath9k. From the initial commit I see:

--- on ath_calcrxfilter()
if (sc->sc_opmode == ATH9K_M_STA || sc->sc_opmode == ATH9K_M_IBSS ||
sc->sc_scanning)
rfilt |= ATH9K_RX_FILTER_BEACON;
---

Seems we're good on 27 for this and this actually turned out to be a regression then.

Luis