i386/121174: if_ral loses performance in FreeBSD 7 (RELENG_7)

[Oliver Herold]

>Number:         121174
>Category:       i386
>Synopsis:       if_ral loses performance in FreeBSD 7 (RELENG_7)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Feb 28 15:10:00 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Oliver Herold
>Release:        FreeBSD 7 stable
>Organization:
>Environment:
FreeBSD olymp.home 7.0-PRERELEASE FreeBSD 7.0-PRERELEASE #0: Tue Feb 26 22:49:53 CET 2008     root at olymp.home:/usr/obj/usr/src/sys/OLYMP  i386
>Description:
Within some hours of use the wifi device drops the performance until just 10-20kb/s. I'm using WPA but using it without any encryption doesn't change anything. At the same time it is possible to use an Atheros device (FreeBSD 7 stable box too) without any drawbacks. I'm able to regain performance if I restart the network, but sometimes I have to shutdown the computer first.

The card:

cardbus0: Expecting link target, got 0x0
ral0: <Ralink Technology RT2661> mem 0x88000000-0x88007fff irq 16 at device 0.0 on cardbus0
ral0: MAC/BBP RT2661B, RF RT2529 (MIMO XR)
ral0: Ethernet address: 00:0e:2e:94:cf:4c
ral0: [ITHREAD]

Vendor Edimax, IEEE 802.11g MIMO cardbus, model EW-7608PG






>How-To-Repeat:
Just surf 1-2h and the performance will drop until almost nothing.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: