* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:29 ` David Mosberger
@ 2016-01-07 16:32 ` Krishna Chaitanya
2016-01-07 16:47 ` David Mosberger
2016-01-07 16:33 ` Ben Greear
2016-01-07 16:59 ` Bruno Randolf
2 siblings, 1 reply; 11+ messages in thread
From: Krishna Chaitanya @ 2016-01-07 16:32 UTC (permalink / raw)
To: David Mosberger; +Cc: Ben Greear, linux-wireless
On Thu, Jan 7, 2016 at 9:59 PM, David Mosberger <davidm@egauge.net> wrote:
>
> Ben,
>
> On Thu, Jan 7, 2016 at 9:24 AM, Ben Greear <greearb@candelatech.com> wrote:
> > On 01/07/2016 08:19 AM, David Mosberger wrote:
> >>
> >> We are seeing a curious issue where WLAN connectivity sometimes
> >> gets stuck until a "wpa_cli reassociate" command is issued.
> >>
> >> At the WPA level, everything appears to be working fine)
> >> (see thread starting at
> >> http://lists.infradead.org/pipermail/hostap/2016-January/034454.html).
> >
> > I don't remember seeing you mention the driver and NIC you are using.
> >
> > I think this is likely a driver bug, so please provide that info.
>
> Sure, we're using rtl8192cu. I started out suspecting a driver bug as
> well, but since we're processing management frames during those
> "stuck" periods just fine (see
> debug output in
> http://lists.infradead.org/pipermail/hostap/2016-January/034459.html),
> I'm not so sure anymore. Like mac80211, we have patched rtl8192cu
> driver with current
> bug-fixes already.
Management frames use a different queue (VO)
from the logs it looks like a data path issue in driver/FW.
The re-association might be clearing/triggering TX in driver
solving the issue.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:32 ` Krishna Chaitanya
@ 2016-01-07 16:47 ` David Mosberger
2016-01-07 16:58 ` Krishna Chaitanya
0 siblings, 1 reply; 11+ messages in thread
From: David Mosberger @ 2016-01-07 16:47 UTC (permalink / raw)
To: Krishna Chaitanya; +Cc: Ben Greear, linux-wireless
On Thu, Jan 7, 2016 at 9:32 AM, Krishna Chaitanya
<chaitanya.mgit@gmail.com> wrote:
> Management frames use a different queue (VO)
> from the logs it looks like a data path issue in driver/FW.
>
> The re-association might be clearing/triggering TX in driver
> solving the issue.
That sounds plausible to me. Is there an easy way to see the queues?
I haven't tried debugfs yet.
--david
--
eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:47 ` David Mosberger
@ 2016-01-07 16:58 ` Krishna Chaitanya
2016-01-07 17:00 ` David Mosberger
0 siblings, 1 reply; 11+ messages in thread
From: Krishna Chaitanya @ 2016-01-07 16:58 UTC (permalink / raw)
To: David Mosberger; +Cc: Ben Greear, linux-wireless
On Thu, Jan 7, 2016 at 10:17 PM, David Mosberger <davidm@egauge.net> wrote:
> On Thu, Jan 7, 2016 at 9:32 AM, Krishna Chaitanya
> <chaitanya.mgit@gmail.com> wrote:
>
>> Management frames use a different queue (VO)
>> from the logs it looks like a data path issue in driver/FW.
>>
>> The re-association might be clearing/triggering TX in driver
>> solving the issue.
>
> That sounds plausible to me. Is there an easy way to see the queues?
> I haven't tried debugfs yet.
We can check pending packets per queue at mac80211, but first
we need some info from driver level. Someone familiar with RTL
should help.
cat /sys/kernel/debug/ieee80211/phy*/queues
If you see non-zero packets here (or) if the queue is stopped
that might explain this behavior...
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:58 ` Krishna Chaitanya
@ 2016-01-07 17:00 ` David Mosberger
0 siblings, 0 replies; 11+ messages in thread
From: David Mosberger @ 2016-01-07 17:00 UTC (permalink / raw)
To: Krishna Chaitanya; +Cc: Ben Greear, linux-wireless
On Thu, Jan 7, 2016 at 9:58 AM, Krishna Chaitanya
<chaitanya.mgit@gmail.com> wrote:
> We can check pending packets per queue at mac80211, but first
> we need some info from driver level. Someone familiar with RTL
> should help.
>
> cat /sys/kernel/debug/ieee80211/phy*/queues
>
> If you see non-zero packets here (or) if the queue is stopped
> that might explain this behavior...
Cool. I'll check that next time it happens, thanks!
--david
--
eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:29 ` David Mosberger
2016-01-07 16:32 ` Krishna Chaitanya
@ 2016-01-07 16:33 ` Ben Greear
2016-01-07 16:45 ` David Mosberger
2016-01-07 16:59 ` Bruno Randolf
2 siblings, 1 reply; 11+ messages in thread
From: Ben Greear @ 2016-01-07 16:33 UTC (permalink / raw)
To: David Mosberger; +Cc: linux-wireless
On 01/07/2016 08:29 AM, David Mosberger wrote:
> Ben,
>
> On Thu, Jan 7, 2016 at 9:24 AM, Ben Greear <greearb@candelatech.com> wrote:
>> On 01/07/2016 08:19 AM, David Mosberger wrote:
>>>
>>> We are seeing a curious issue where WLAN connectivity sometimes
>>> gets stuck until a "wpa_cli reassociate" command is issued.
>>>
>>> At the WPA level, everything appears to be working fine)
>>> (see thread starting at
>>> http://lists.infradead.org/pipermail/hostap/2016-January/034454.html).
>>
>> I don't remember seeing you mention the driver and NIC you are using.
>>
>> I think this is likely a driver bug, so please provide that info.
>
> Sure, we're using rtl8192cu. I started out suspecting a driver bug as
> well, but since we're processing management frames during those
> "stuck" periods just fine (see
> debug output in
> http://lists.infradead.org/pipermail/hostap/2016-January/034459.html),
> I'm not so sure anymore. Like mac80211, we have patched rtl8192cu
> driver with current
> bug-fixes already.
I have no experience with that chip, but wifi is a tricky beast. Could be
a power-save issue perhaps. I assume you have sniffed to see if any frames
are going out on the air during the time of trouble?
If correct packets go out on the air and AP doesn't answer, then likely AP problem.
If pkts don't get on the air, then check to see if they at least get to
the driver.
If they don't get to the driver, then probably it is a kernel/stack issue.
If they get to the driver but not on the air, then NIC and/or it's firmware
and/or the driver is likely the culprit.
Thanks,
Ben
>
> --david
>
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:33 ` Ben Greear
@ 2016-01-07 16:45 ` David Mosberger
0 siblings, 0 replies; 11+ messages in thread
From: David Mosberger @ 2016-01-07 16:45 UTC (permalink / raw)
To: Ben Greear; +Cc: linux-wireless
Ben,
On Thu, Jan 7, 2016 at 9:33 AM, Ben Greear <greearb@candelatech.com> wrote:
> Could be
> a power-save issue perhaps.
That was our thought, too. Particularly, since if there is steady
traffic (at least a ping every 8 seconds), the problem does not appear
to occur.
However, the rtl8192cu doesn't support power-saving mode and in any
case, we made sure it's off:
# iw wlan0 get power_save
Power save: off
> I assume you have sniffed to see if any frames are going out on the air during the time of trouble?
No, I'm not actually sure how I'd do that. The site we see this most
frequently with is
remote and we don't have any special WiFi packet sniffer.
> If correct packets go out on the air and AP doesn't answer, then likely AP
> problem.
Not likely an AP problem, since we're seeing this with multiple APs of
different brands etc.
> If pkts don't get on the air, then check to see if they at least get to
> the driver.
Yeah, that should be easy to do, I suppose. We had rtl8192cu
debugging turned on
before but at that time it didn't help.
> If they don't get to the driver, then probably it is a kernel/stack issue.
>
> If they get to the driver but not on the air, then NIC and/or it's firmware
> and/or the driver is likely the culprit.
Thanks for your thoughts!
--david
--
eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:29 ` David Mosberger
2016-01-07 16:32 ` Krishna Chaitanya
2016-01-07 16:33 ` Ben Greear
@ 2016-01-07 16:59 ` Bruno Randolf
2016-01-07 17:32 ` David Mosberger
2 siblings, 1 reply; 11+ messages in thread
From: Bruno Randolf @ 2016-01-07 16:59 UTC (permalink / raw)
To: David Mosberger, Ben Greear; +Cc: linux-wireless
On 01/07/2016 04:29 PM, David Mosberger wrote:
> On Thu, Jan 7, 2016 at 9:24 AM, Ben Greear <greearb@candelatech.com> wrote:
>> On 01/07/2016 08:19 AM, David Mosberger wrote:
>>>
>>> We are seeing a curious issue where WLAN connectivity sometimes
>>> gets stuck until a "wpa_cli reassociate" command is issued.
>>>
>>> At the WPA level, everything appears to be working fine)
>>> (see thread starting at
>>> http://lists.infradead.org/pipermail/hostap/2016-January/034454.html).
>>
>> I don't remember seeing you mention the driver and NIC you are using.
>>
>> I think this is likely a driver bug, so please provide that info.
>
> Sure, we're using rtl8192cu. I started out suspecting a driver bug as
> well, but since we're processing management frames during those
> "stuck" periods just fine (see
Although I have not checked if the "wpa_cli reassociate" command helps,
I have seen rtl8192cu get "stuck" in similar ways. Maybe you can give
the new rtl8xxxu driver from Jes Sorensen try? It has less features, but
works more reliable, IMHO...
bruno
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: lost connectivity until "wpa_cli reassociate" is issued
2016-01-07 16:59 ` Bruno Randolf
@ 2016-01-07 17:32 ` David Mosberger
0 siblings, 0 replies; 11+ messages in thread
From: David Mosberger @ 2016-01-07 17:32 UTC (permalink / raw)
To: Bruno Randolf; +Cc: Ben Greear, linux-wireless
On Thu, Jan 7, 2016 at 9:59 AM, Bruno Randolf <br1@einfach.org> wrote:
> Although I have not checked if the "wpa_cli reassociate" command helps,
> I have seen rtl8192cu get "stuck" in similar ways. Maybe you can give
> the new rtl8xxxu driver from Jes Sorensen try? It has less features, but
> works more reliable, IMHO...
Oh, boy, switching to a completely different driver is not what I'd
like to do at this
stage, but perhaps it's the right thing to do. Thanks for the suggestion!
I'll check with Jes.
--david
--
eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768
^ permalink raw reply [flat|nested] 11+ messages in thread