if_ral regression

I upgraded my router cum firewall cum access point (soekris net4801 with
a cheap third-party ralink-based wlan adapter) from RELENG_6 to HEAD and
noticed what seems to be a regression in if_ral.  After a certain amount
of use (i.e. actually having a client connected to it and transferring
data), the connection falters, and eventually the client can no longer
see even see the access point in a scan.  Restarting the interface on
the router (/etc/rc.d/netif restart ral0) fixes it.  I now have a cron
job that does this every five minutes.  I still get occasional outages,
but all I have to do is wait a few minutes for the cron job to kick in.

Outages are clearly related to traffic; a sure-fire way to trigger one
is to start a backup job on my laptop (rsync to my file server).  I will
lose the wlan connection repeatedly until I either stop trying or run
the script with a bandwidth limit.

des_at_soe ~% uname -a
FreeBSD soe.des.no 8.0-CURRENT FreeBSD 8.0-CURRENT #0: Sat Dec 15 20:46:29 UTC 2007     des_at_pwd.des.no:/usr/obj/usr/src/sys/soe  i386
des_at_soe ~% kldstat -v
Id Refs Address    Size     Name
 1   18 0xc0400000 33fdfc   kernel (/boot/soe/kernel)
 2    1 0xc0740000 7690     if_sis.ko (/boot/soe/if_sis.ko)
 3    2 0xc0748000 1dbe0    miibus.ko (/boot/soe/miibus.ko)
 4    1 0xc0766000 18e28    if_ral.ko (/boot/soe/if_ral.ko)
 5    4 0xc077f000 2a95c    wlan.ko (/boot/soe/wlan.ko)
 6    1 0xc07aa000 2cb0     wlan_acl.ko (/boot/soe/wlan_acl.ko)
 7    1 0xc07ad000 1924     wlan_scan_ap.ko (/boot/soe/wlan_scan_ap.ko)
 8    1 0xc107f000 6000     geom_md.ko (/boot/soe/geom_md.ko)
 9    1 0xc10f9000 2000     pflog.ko (/boot/soe/pflog.ko)
10    1 0xc10fb000 2f000    pf.ko (/boot/soe/pf.ko)
11    4 0xc118d000 a000     netgraph.ko (/boot/soe/netgraph.ko)
12    1 0xc119c000 3000     ng_ether.ko (/boot/soe/ng_ether.ko)
13    1 0xc11a8000 5000     ng_pppoe.ko (/boot/soe/ng_pppoe.ko)
14    1 0xc11ad000 4000     ng_socket.ko (/boot/soe/ng_socket.ko)
des_at_soe ~% grep ral0 /var/run/dmesg.boot
ral0: <Ralink Technology RT2560> mem 0xa0004000-0xa0005fff irq 11 at device 10.0 on pci0
ral0: MAC/BBP RT2560 (rev 0x04), RF RT2525
ral0: Ethernet address: 00:08:a1:8d:2f:73
ral0: [ITHREAD]
des_at_soe ~% pciconf -lv
[...]
ral0_at_pci0:0:10:0:       class=0x028000 card=0x00201371 chip=0x02011814 rev=0x01 hdr=0x00
    vendor     = 'Ralink Technology, Corp'
    device     = '0x03011814 Zonet ZEW1601 (Ralink Chipset) 802.11b/g WLAN Card'
    class      = network
[...]
des_at_soe ~% ifconfig ral0
ral0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        ether 00:08:a1:8d:2f:73
        inet 10.0.11.1 netmask 0xffffff00 broadcast 10.0.11.255
        media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap>
        status: associated
        ssid des.no channel 1 (2412 Mhz 11g) bssid 00:08:a1:8d:2f:73
        authmode OPEN privacy OFF txpower 50 scanvalid 60 bgscan
        bgscanintvl 300 bgscanidle 250 roam:rssi11g 7 roam:rate11g 5
        protmode CTS dtimperiod 1

DES
-- 
Dag-Erling Smørgrav - des_at_des.no