Re: ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue...?

[Jamie Stuart <jamie@onebillion.org>]

Hi Stanis,

Our environment has the following wireless config (MT7620A):

config wifi-device 'radio0'
	option type 'mac80211'
	option channel 'auto'
	option hwmode '11g'
	option path 'platform/10180000.wmac'
	option txpower '20'
	option country 'GB'
	option htmode 'HT40'
	option noscan '1'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option encryption 'psk2+aes'
	option key =E2=80=98KEY'
	option maxassoc '96'
	option ssid =E2=80=99SSID'
	option disassoc_low_ack =E2=80=980'


The 30 clients are all Apple iPads (a mixture of iPad mini and mini 2, =
running iOS 9-11). During this testing period, all clients were =
simultaneously downloading files from the devices=E2=80=99 sdcard =
(served via nginx running on the device). Although this is not a typical =
use-case, it was useful in stress-testing the wireless setup.

We=E2=80=99ll try your patches Stanis.
Daniel - forgive the stupid question, but how do we apply Stanis=E2=80=99 =
patches atop your staging tree (or both yours and Stanis=E2=80=99 atop =
trunk?)



> On 7 Mar 2018, at 14:27, Stanislaw Gruszka <sgruszka@redhat.com> =
wrote:
>=20
> On Thu, Mar 01, 2018 at 04:30:10PM +0100, Daniel Golle wrote:
>> [forwarding to all other involved players]
>>=20
>> On Thu, Mar 01, 2018 at 05:50:51PM +0300, Jamie Stuart wrote:
>>> Hi Daniel,
>>> The driver seems much improved after this fix.
>>=20
>> it's about those two
>> [PATCH 1/2] rt2x00: pause almost full queue early
>> [PATCH 2/2] rt2x00: do not pause queue unconditionally on error path
>>=20
>>> Under very heavy load (30 clients downloading multi-GB files from SD =
card on the server concurrently), wifi dies with errors:
>=20
> This is some testbed? Could you share how did you setup such
> environment and what are client devices ?
>=20
>>> [ 7794.230376] ieee80211 phy0: rt2x00lib_rxdone_read_signal: Warning =
- Frame received with unrecognized signal, mode=3D0x0001, signal=3D0x010c,=
 type=3D4
>=20
> This is indicator that HW/FW has a problem. There could be various
> reasons for that. One possible I can also observe in my setup,is =
strange
> mishmash of seq  on frames which were not acked in BlockACK and
> had to be resent. This can happen when many frames are wrongly decoded
> (i.e. when there is bad radio condition or we have not correct low =
level
> RF/BBP setup for a Ralink device). To mitigate that problem we can
> limit length of agreggeted AMPDU frame.
>=20
> I attached two patches which do that. One for RX side second for TX =
side.
> Please check if they make a diffrent. You can also hardcode ba_size =3D =
0
> for those 30 clients setup.
>=20
> Note the patches can cause (possibly small) perfromance degradation on
> good setups.=20
>=20
> Mathias, could you check them as well and see if they do not cause
> performance regression on your device ? Lastly when I changed ba_size
> setting, it was a problem on your setup.
>=20
>>> Thu Mar  1 16:36:47 2018 kern.err kernel: [ 8702.146403] ieee80211 =
phy0: rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in =
the non-full queue 2
>>> Thu Mar  1 16:36:47 2018 kern.err kernel: [ 8702.146403] Please file =
bug report to http://rt2x00.serialmonkey.com
>>> Thu Mar  1 16:36:48 2018 kern.err kernel: [ 8702.288149] ieee80211 =
phy0: rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in =
the non-full queue 2
>>> Thu Mar  1 16:36:48 2018 kern.err kernel: [ 8702.288149] Please file =
bug report to http://rt2x00.serialmonkey.com
>>> Thu Mar  1 16:36:48 2018 kern.err kernel: [ 8702.380761] ieee80211 =
phy0: rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in =
the non-full queue 2
>>> Thu Mar  1 16:36:48 2018 kern.err kernel: [ 8702.380761] Please file =
bug report to http://rt2x00.serialmonkey.com
>=20
> For those errors I recommend to remove=20
>=20
> 600-23-rt2x00-rt2800mmio-add-a-workaround-for-spurious-TX_F.patch
>=20
> patch. Whould be good if OpenWRT developers could apply this patch =
only
> on target where it is really needed, not for all rt2800 devices.
>=20
> Thanks
> Stanislaw