kern/42461: ale(4) very choosy about Ethernet switch

[netbsd%precedence.co.uk@localhost]

>Number:         42461
>Category:       kern
>Synopsis:       ale(4) only works in certain switches with certain speeds
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Dec 16 13:55:00 +0000 2009
>Originator:     Stephen Borrill
>Release:        NetBSD 5.0_STABLE and -current
>Organization:
        
>Environment:
        
        
System: NetBSD 5.99.22 (MONOLITHIC)
Architecture: i386
Machine: i386
>Description:
The ale(4) interface on my EeePC 900A does not detect a carrier on all
switches and speeds.

When plugged into a gigabit port on a Linksys SRW224 switch, the switch
shows a link (not full-speed of course), but ifconfig shows no carrier.
DHCP cannot get an address.

When plugged into a 10/100 port on the same Linksys switch, the connection
works. 

When plugged into a cheap 10/100 switch, the link light on the switch goes
out during the kernel autoconf messages and does not recover until the
switch itself is powercycled. When connected to this switch I get the
following errors:
ale0: DMA read error ! -- resetting
ale0: could not disable Tx/Rx MAC(0x000000008)!

I'm network booting in all cases, so pxeboot is talking to the network happily.
Linux also works fine in all cases.

Device is (hand copied):
ale0 at pci3 dev 0 function 0: Attansic/Atheros L1E Ethernet
al0: AR8113 (L2E RevA), ioapic0 pin 19
atphy0 at ale0 phy 0: L1 10/100/1000 PHY, rev.9
        
>How-To-Repeat:
Try an Asus EeePC 900A with various switches
>Fix:
        

>Unformatted: