| I added a 3com 3c905b NIC into a pci slot and installed
| a -current snapshot (1.5 ZA) into it. After installation,
| I left it to run overnight pinging another machine with
| ping -i 60 -s 2500, to see if it stays up. Well, it didn't.

| Sometime at night, it barfed:
|
| panic: psycho0: uncorrectable DMA error AFAR 2524608 pa ffffffffffffffff
| AFSR 4100ff0020800000:
| 4100ff0020800000<BLK,P_DTE,P_DRD>
| kdb breakpoint at 132f8f0
| Stopped at      cpu_Debugger+0x4:       nop
| db>

This is an indication that some random device is trying to
do DMA to an invalid DMA address.  In fact, address 2524608
is completely out of range for valid DMA addresses.  So far
I have never seen this happen on machines with only the 
board devices on them.

Eduardo