I have two VIA NAB-7410 boards with 4x Intel 82541GI gigabit adapters. On both boards, Linux occasionally stops responding to Ethernet frames. The problem goes away when another interrupt is triggered, either by USB or RS232. The boards are running different distros: OpenWRT (3.18.20) and Debian (3.16.0-4-686-pae). Is this an e1000 driver bug?
Update 2015-10-19: I've discovered that the problematic machines are generating ping replies that get queued in a transmit buffer but are not sent out to the network until a USB or serial interrupt. Also, something is putting the CPU to sleep and disabling timer interrupts, as the "uptime" value does not change while the system is unresponsive.
Update 2015-10-26: It seems that the south bridge chip is triggering an SMI routine after periods of no "primary" interrupts, i.e. USB, disk or serial interrupts. See this PDF on page 168, "Legacy Power Management Timers".
How do I disable this "feature"?