"no buffer space available" EDIMAX EW-7811UN Wireless USB Adapter

Sun Apr 10 11:02:21 UTC 2016

Hi,

I got an EDIMAX EW-7811UN Wireless USB Adapter [1]
(150 Mbit/s, IEEE802.11b/g/n) to use on a few systems that
don't yet have supported onboard adapters.

While using this I get `no buffer space available` regularly,
including from dhclient. This sometimes requires me to
hard reboot to regain network connectivity. Is there anything
I can do about this?

BTW specific recommendations on better-supported USB widgets
are welcome.

Hopefully relevant/useful info below.

[1]:
http://www.edimax.com/edimax/merchandise/merchandise_detail/data/edimax/global/wireless_adapters_n150/ew-7811un

root at nucl:~ # uname -v
FreeBSD 10.3-RELEASE #0 r297264: Fri Mar 25 02:10:02 UTC 2016
root at releng1.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC

root at nucl:~ # dmesg | egrep -i 'wlan|urtwn'
urtwn0: <vendor 0x0bda product 0x8191, class 0/0, rev 2.00/2.00, addr 3>
on usbus0
urtwn0: MAC/BB RTL8188CUS, RF 6052 1T1R
wlan0: Ethernet address: 74:da:38:41:6e:7f
wlan0: link state changed to UP

root at nucl:~ # kldstat
Id Refs Address            Size     Name
 1   68 0xffffffff80200000 17bc680  kernel
 2    1 0xffffffff819bd000 2fc428   zfs.ko
 3   12 0xffffffff81cba000 6040     opensolaris.ko
 4    1 0xffffffff81cc1000 a858     if_tap.ko
 5    1 0xffffffff81ccc000 11c28    if_bridge.ko
 6    2 0xffffffff81cde000 8490     bridgestp.ko
 7    1 0xffffffff81ce7000 157c0    aio.ko
 8    1 0xffffffff81cfd000 1598     accf_data.ko
 9    1 0xffffffff81cff000 1850     accf_dns.ko
10    1 0xffffffff81d01000 4a70     coretemp.ko
11    1 0xffffffff81d06000 1d6080   vmm.ko
12    1 0xffffffff81edd000 4d48     nmdm.ko
13    1 0xffffffff81ee2000 2188     dtraceall.ko
14    2 0xffffffff81ee5000 7040     profile.ko
15   11 0xffffffff81eed000 591a0    dtrace.ko
16    2 0xffffffff81f47000 1d548    systrace_freebsd32.ko
17    2 0xffffffff81f65000 1df50    systrace.ko
18    2 0xffffffff81f83000 3458     sdt.ko
19    2 0xffffffff81f87000 6730     lockstat.ko
20    2 0xffffffff81f8e000 620f0    fasttrap.ko
21    2 0xffffffff81ff1000 9658     fbt.ko
22    2 0xffffffff81ffb000 5ee8     dtnfscl.ko
23    2 0xffffffff82001000 60c0     dtmalloc.ko
24    1 0xffffffff82008000 3108     cc_htcp.ko
25    1 0xffffffff82711000 fdb4     geom_eli.ko
26    1 0xffffffff82721000 1f55e    crypto.ko
27    1 0xffffffff82741000 2ba8     uhid.ko
28    1 0xffffffff82744000 11da8    if_urtwn.ko

root at nucl:~ # cat /etc/rc.conf
ifconfig_em0="DHCP"
ifconfig_em0_ipv6="inet6 accept_rtadv"
# wifi
wlans_urtwn0="wlan0"
ifconfig_wlan0="WPA DHCP"
root at nucl:~ #

root at nucl:~ # ifconfig wlan0 list caps
drivercaps=2181c001<STA,SHSLOT,SHPREAMBLE,MONITOR,WPA1,WPA2,BGSCAN>

root at nucl:~ # ifconfig -a
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
1500
	options=4019b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,VLAN_HWTSO>
	ether b8:ae:ed:78:fb:0c
	inet6 fe80::baae:edff:fe78:fb0c%em0 prefixlen 64 scopeid 0x1
	inet6 2001:470:26:2bf:baae:edff:fe78:fb0c prefixlen 64 autoconf
	inet 10.0.0.11 netmask 0xffffff00 broadcast 10.0.0.255
	nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
	media: Ethernet autoselect (1000baseT <full-duplex>)
	status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
	options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
	inet6 ::1 prefixlen 128
	inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2
	inet 127.0.0.1 netmask 0xff000000
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
urtwn0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
2290
	ether 74:da:38:41:6e:7f
	nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
	media: IEEE 802.11 Wireless Ethernet autoselect mode 11g
	status: associated
wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
1500
	ether 74:da:38:41:6e:7f
	inet 10.0.0.41 netmask 0xffffff00 broadcast 10.0.0.255
	nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
	media: IEEE 802.11 Wireless Ethernet OFDM/54Mbps mode 11g
	status: associated
	ssid cottlehubers channel 10 (2457 MHz 11g) bssid
	bc:f2:af:e3:1e:92
	country US authmode WPA2/802.11i privacy ON deftxkey UNDEF
	AES-CCM 3:128-bit txpower 0 bmiss 7 scanvalid 60 bgscan
	bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode
	CTS
	roaming MANUAL

root at nucl:~ # netstat -m
1024/2021/3045 mbufs in use (current/cache/total)
1023/1007/2030/1011284 mbuf clusters in use (current/cache/total/max)
1023/1001 mbuf+clusters out of packet secondary zone in use
(current/cache)
0/4/4/505642 4k (page size) jumbo clusters in use
(current/cache/total/max)
0/0/0/149819 9k jumbo clusters in use (current/cache/total/max)
0/0/0/84273 16k jumbo clusters in use (current/cache/total/max)
2302K/2535K/4837K bytes allocated to network (current/cache/total)
0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
0/0/0 requests for mbufs delayed (mbufs/clusters/mbuf+clusters)
0/0/0 requests for jumbo clusters delayed (4k/9k/16k)
0/0/0 requests for jumbo clusters denied (4k/9k/16k)
0 requests for sfbufs denied
0 requests for sfbufs delayed
0 requests for I/O initiated by sendfile

root at nucl:~ # sysctl net.wlan
net.wlan.0.inact_init: 30
net.wlan.0.inact_auth: 180
net.wlan.0.inact_probe: 30
net.wlan.0.inact_run: 300
net.wlan.0.bmiss_max: 2
net.wlan.0.debug: 0
net.wlan.0.driver_caps: 562085889
net.wlan.0.%parent: urtwn0
net.wlan.mesh.maxholding: 2
net.wlan.mesh.maxretries: 2
net.wlan.mesh.backofftimeout: 5000
net.wlan.mesh.confirmtimeout: 40
net.wlan.mesh.holdingtimeout: 40
net.wlan.mesh.retrytimeout: 40
net.wlan.mesh.gateint: 10000
net.wlan.hwmp.inact: 5000
net.wlan.hwmp.rootconfint: 2000
net.wlan.hwmp.rannint: 1000
net.wlan.hwmp.rootint: 2000
net.wlan.hwmp.roottimeout: 5000
net.wlan.hwmp.net_diameter_traversal_time: 512
net.wlan.hwmp.maxpreq_retries: 3
net.wlan.hwmp.pathlifetime: 5000
net.wlan.hwmp.targetonly: 0
net.wlan.addba_maxtries: 3
net.wlan.addba_backoff: 10000
net.wlan.addba_timeout: 250
net.wlan.recv_bar: 1
net.wlan.ampdu_age: 500
net.wlan.debug: 0
net.wlan.cac_timeout: 60
net.wlan.nol_timeout: 1800