DMA boundary bug and runs with PCI-X mode. watchdog timeout was
observed on BCM5704 which lives behind certain PCI-X bridge(e.g.
AMD 8131 PCI-X bridge). It's still not clear whether the root
cause came from that PCI-X bridge or not. The watchdog timeout
indicates the issue is in TX path. If the bridge reorders TX
mailbox write accesses it would generate all kinds of problems but
I'm not sure. This should be revisited.
Tested by: Michael L. Squires (mikes <> siralan dot org)