David Campbell (campbell@torque.net)
Thu, 10 Dec 1998 07:09:12 +0800
> >The port->ops structure has changed. epp_write_block and epp_read_block
> >now provide a callback, whereas previously they didn't. ('ECP+EPP'
> >chipsets can DMA EPP.)
> ^^^^^^^
> Ouah! I haven't ever thought about this. It would really improve the
> ZIP driver. Is this particular to some SMC like chips or just to one or more
> chips?
>
> David C.: did you ever try this before?
Nope, lack of suitable test hardware.
I *think* my new mainboard is capable of ECP+EPP, but as Nicolas should know
ECP+EPP is one of those gray areas of parallel port hardware where no-one
really knows what is truely going on. It took me several months before I
figured out what a little cryptic "post-it" note that SMC left in one of their
pdf files actually meant (EPP writes go via the FIFO, EPP reads are direct).
Without the ECP sync routine, EPP under ECP+EPP is impossible.
The latest pdfs I have from SMC are lacking the "post-it" note or any reference
to a link between EPP and the FIFO. Could SMC have changed the EPP so it does
not use the FIFO? Or more likely forgot to add it to the current pdfs.
At this stage someone (probably myself) need to check and verify if EPP DMA is
possible for the ZIP drive.
David Campbell
=======================================================
campbell@torque.net
Check http://www.torque.net/parport for all Linux parallel port solutions.
Current project list:
a) Madly fixing up web pages....
b) Maintain Linux ZIP drivers (need to update docs)
c) Create Linux chipset specific parport drivers
Any assistance to clearing this list most welcome
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This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 10:18:53 EST