I've been having some issues with an Intel gigabit ethernet card and 
device timeouts lately.  I have a fileserver set up here at my house 
(duron 900, 256MB ram) running NetBSD 2.0.2 kernel and userland.  The 
machine also serves as a dns server and web proxy for the house.  It's 
connected to the rest of the LAN (2 Windows machines both with gigabit 
cards, and a Mac with built in gigE) via a Dell 24-port gigabit switch 
and cat5e cabling.

I've had the gigabit card (Intel i82540EM with the wm* driver) for a 
while, and never really had any troubles with it.  I bought an AT&T 
802.11g pci card (AT&T 6500G with the ath* driver) to add to the 
machine so it could act as a WAP, and things have sort of gone downhill 
from there.  I've been getting a lot of the following from the gigabit 
card lately, mostly whenever doing sustained transfers such as 
listening to mp3s via an NFS mount or copying files across the network. 
  These cause the network to "skip" for as long as 15 seconds, sometimes 
causing my Mac to ask if I want to disconnect all NFS shares to that 
machine.

        wm0: device timeout (txfree 147 txsfree 16 txnext 119)
        wm0: device timeout (txfree 95 txsfree 0 txnext 42)
        wm0: device timeout (txfree 136 txsfree 16 txnext 65)
        wm0: device timeout (txfree 111 txsfree 0 txnext 54)

I've tried the following to attempt to fix this:

- upgraded from 2.0 to 2.0.2 to pull in some wm* changes that occured 
there
- upgraded the machine's BIOS to the latest
- pulled the ath0 card.  This causes the problem to go away quite a 
bit, but doesn't fully correct it.
- switched the card's PCI slot
- checked for IRQ conflicts
- changed cabling
- changed ports the card is plugged into on the switch
- tried using SMB vs NFS

Nothing beyond pull the ath0 card seemed to make much of a difference.  
The machine's dmesg is pasted below.  Thanks for any help.

Tim

dmesg:

NetBSD 2.0.2 (tulmad2) #0: Wed Mar 23 18:41:46 MST 2005
         tim@filegeek:/usr/src/sys/arch/i386/compile/tulmad2
total memory = 383 MB
avail memory = 371 MB
BIOS32 rev. 0 found at 0xfb210
mainbus0 (root)
cpu0 at mainbus0: (uniprocessor)
cpu0: AMD Duron (686-class), 902.12 MHz, id 0x631
cpu0: features c1c7f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR>
cpu0: features c1c7f9ff<PGE,MCA,CMOV,PAT,PSE36,PN,MMXX,MMX>
cpu0: features c1c7f9ff<FXSR,3DNOW2,3DNOW>
cpu0: I-cache 64 KB 64B/line 2-way, D-cache 64 KB 64B/line 2-way
cpu0: L2 cache 64 KB 64B/line 16-way
cpu0: ITLB 16 4 KB entries fully associative, 8 4 MB entries fully 
associative
cpu0: DTLB 24 4 KB entries fully associative, 8 4 MB entries 4-way
cpu0: 8 page colors
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
pchb0 at pci0 dev 0 function 0
pchb0: VIA Technologies VT8363 KT133 System Controller (rev. 0x03)
agp0 at pchb0: aperture at 0xd8000000, size 0x10000000
ppb0 at pci0 dev 1 function 0: VIA Technologies VT8363 KT133 PCI to AGP 
Bridge (rev. 0x00)
pci1 at ppb0 bus 1
pci1: i/o space, memory space enabled
vga0 at pci1 dev 0 function 0: Nvidia Corporation GeForce2 MX (rev. 
0xa1)
wsdisplay0 at vga0 kbdmux 1: console (80x25, vt100 emulation)
wsmux1: connecting to wsdisplay0
pcib0 at pci0 dev 7 function 0
pcib0: VIA Technologies VT82C686A (Apollo KX133) PCI-ISA Bridge (rev. 
0x40)
viaide0 at pci0 dev 7 function 1
viaide0: VIA Technologies VT82C686A (Apollo KX133) ATA100 controller
viaide0: bus-master DMA support present
viaide0: primary channel configured to compatibility mode
viaide0: primary channel interrupting at irq 14
atabus0 at viaide0 channel 0
viaide0: secondary channel configured to compatibility mode
viaide0: secondary channel interrupting at irq 15
atabus1 at viaide0 channel 1
uhci0 at pci0 dev 7 function 2: VIA Technologies VT83C572 USB 
Controller (rev. 0x1a)
uhci0: interrupting at irq 12
usb0 at uhci0: USB revision 1.0
uhub0 at usb0
uhub0: VIA Technologies UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1 at pci0 dev 7 function 3: VIA Technologies VT83C572 USB 
Controller (rev. 0x1a)
uhci1: interrupting at irq 12
usb1 at uhci1: USB revision 1.0
uhub1 at usb1
uhub1: VIA Technologies UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
VIA Technologies VT82C686A SMBus Controller (miscellaneous bridge, 
revision 0x40) at pci0 dev 7 function 4 not configured
wm0 at pci0 dev 10 function 0: Intel i82540EM 1000BASE-T Ethernet, rev. 
2
wm0: interrupting at irq 10
wm0: 32-bit 33MHz PCI bus
wm0: 64 word (6 address bits) MicroWire EEPROM
wm0: Ethernet address 00:07:e9:19:c8:70
makphy0 at wm0 phy 1: Marvell 88E1011 Gigabit PHY, rev. 3
makphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 
1000baseT-FDX, auto
ath0 at pci0 dev 13 function 0
ath0: interrupting at irq 11
ath0: mac 5.9 phy 4.3 5ghz radio 4.6
ath0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
ath0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 
24Mbps 36Mbps 48Mbps 54Mbps
ath0: 802.11 address: 00:0d:14:01:f0:86
pdcide0 at pci0 dev 14 function 0
pdcide0: Promise Ultra100TX2/ATA Bus Master IDE Accelerator (rev. 0x02)
pdcide0: bus-master DMA support present
pdcide0: primary channel configured to native-PCI mode
pdcide0: using irq 10 for native-PCI interrupt
atabus2 at pdcide0 channel 0
pdcide0: secondary channel configured to native-PCI mode
atabus3 at pdcide0 channel 1
isa0 at pcib0
lpt0 at isa0 port 0x378-0x37b irq 7
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: PC speaker
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
isapnp0: no ISA Plug 'n Play devices found
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
Kernelized RAIDframe activated
atapibus0 at atabus0: 2 targets
cd0 at atapibus0 drive 0: <MATSHITA CR-587, , 7S14> cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 2
cd0(viaide0:0:0): using PIO mode 4, DMA mode 2 (using DMA data 
transfers)
wd0 at atabus1 drive 0: <ST310211A>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 9541 MB, 19386 cyl, 16 head, 63 sec, 512 bytes/sect x 19541088 
sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(viaide0:1:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using 
DMA data transfers)
wd1 at atabus2 drive 0: <WDC WD1600JB-00DUA0>
wd1: drive supports 16-sector PIO transfers, LBA48 addressing
wd1: 149 GB, 310101 cyl, 16 head, 63 sec, 512 bytes/sect x 312581808 
sectors
wd1: 32-bit data port
wd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd1(pdcide0:0:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using 
DMA data transfers)
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs