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

[Johann Klammer]

Johann Klammer wrote:
[...]
> With the chipset I'm using(vt1211 superio) it seems necessary to 
> initiate the first handshake manually by lowering PeriphClk. (the line 
> with parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);) Else it 
> hangs.
Oops wrong. It should be: It seems necessary to 
initiate the first handshake manually by raising HostAck==nAUTOFD. The code is fine though.

> I'll also try it on a more ancient intel mainboard later to see whether 
> it is hardware specific.
Done. It works exactly the same on old Intel 440BX. DMA also hangs without frob_control...