>Number:         30560
>Category:       port-alpha
>Synopsis:       i82557.c reports SCB timed out consistently
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-alpha-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 19 18:47:00 +0000 2005
>Originator:     Stephen Jones
>Release:        NetBSD 2.0.2_STABLE
>Organization:
SDF Public Access UNIX System 
>Environment:
System: NetBSD ol 2.0.2_STABLE NetBSD 2.0.2_STABLE (sdf) #0: Sun Jun 12 15:36:54 UTC 2005 root@vinland:/var/netbsd/arch/alpha/compile/sdf alpha
Architecture: alpha
Machine: alpha
>Description:

The i82557.c driver reports SCB timed out consistently, especially with
network activity.  The result is the interface shuts down for a brief period
on all network dependent processes
>How-To-Repeat:

Install any 2.x release of NetBSD on an Alpha with fxp (i82557) ethernet
interface(s) configured.

>Fix:

Unknown.  Izumi Tsutsui says:

"IMHO, the hardware design of fxp(4) by Intel guys doesn't suit
 most RISC CPUs (it can't prevent some race conditions
 because it has DMA descriptors in uint16_t)"

He also suggests that NetBSD should adopt OpenBSD's 'fix':

http://www.openbsd.org/cgi-bin/cvsweb/src/sys/dev/ic/fxpreg.h?sortby=date#rev1.7