[Linux-parport] ASYNC I/O Reason: Reverse transfers are _slow_

[Johann Klammer]

Dirk Jagdmann wrote:
> Hallo Johann,
> 
> in what mode did you hook up and talk to the microcontroller? EPP and
It uses ECP protocol using ppdev read() and write() operations in ECP 
mode. The primary hassle seem to be the lack of DMA support for reads.
> ECP modes should provide adequate performance, but if you "invent"
> your own protocol, or trigger every byte/nibble with your own function
> calls to set the parallel port lines, it will always be slow.
>