On Wed, Apr 18, 2001 at 11:06:15PM +0200, Tommy Kjellqvist wrote:
> Does the parport driver use DMA in both EPP and ECP mode?
No. I don't think that there are any chips which support DMA in EPP.
The parport driver will use DMA for ECP if
(a) it's configured to in the kernel (CONFIG_PARPORT_PC_FIFO),
(b) the hardware is there for it to use, and
(c) the module parameter 'irq=auto' (or kernel command line parameter
parport=auto) is used.
> Whitch mode can be expected to deliver the highest performance?
It depends on your application, I think. ECP seems to be quite
popular for newer devices though.
> Is there any important differences between the two modes except the
> fact that when transfering data from a peripherial to the host using
> ECP the peripherial initiate the transfer?
Well, they are just different protocols. With both modes the
peripheral gets to say whether it has data to transfer, AFAIR.
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This archive was generated by hypermail 2b29 : Thu Apr 19 2001 - 03:08:08 EDT