ab431312b4
ADMtek AL981 "Comet" chipset. The AL981 is yet another DEC tulip clone, except with simpler receive filter options. The AL981 has a built-in transceiver, power management support, wake on LAN and flow control. This chip performs extremely well; it's on par with the ASIX chipset in terms of speed, which is pretty good (it can do 11.5MB/sec with TCP easily). I would have committed this driver sooner, except I ran into one problem with the AL981 that required a workaround. When the chip is transmitting at full speed, it will sometimes wedge if you queue a series of packets that wrap from the end of the transmit descriptor list back to the beginning. I can't explain why this happens, and none of the other tulip clones behave this way. The workaround this is to just watch for the end of the transmit ring and make sure that al_start() breaks out of its packet queuing loop and waiting until the current batch of transmissions completes before wrapping back to the start of the ring. Fortunately, this does not significantly impact transmit performance. This is one of those things that takes weeks of analysis just to come up with two or three lines of code changes. |
||
|---|---|---|
| .. | ||
| amd64 | ||
| conf | ||
| include | ||
| isa | ||
| pci | ||
| Makefile | ||