smcs91c111 driver cant allocate memory

[daddyritz]

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.
*/