Anyone see unable to Tx with smc9000 driver for smcs91c111 chip
allocation ints never happen and the chip has no memory left in the
MMU
/*
- Chip is older than the 91C111 which means
- the MCR is implemented. We reserve 1 packets-worth
- of memory for transmit, to prevent TX MMU allocations
- from pending forever. It appears that on older chips
- (not the 111) releasing an RX packet while a TX alloc is
- pending screws up the MMU. On these chips, we limit
- the memory that receive can use, to prevent a deadlock
- condition whereby all memory is used up by unprocessed
- receive packets, and the transmitter has just issued
- an allocate command.
*/