Subject: Re: How about to config Hayes ESP with glue device rather than magical option?
To: enami tsugutomo <enami@but-b.or.jp>
From: Chris G. Demetriou <cgd@pa.dec.com>
List: current-users
Date: 09/10/1997 09:34:57
> "Chris G. Demetriou" <cgd@pa.dec.com> writes:
> 
> > I don't know what it means, but it's wrong.  8-)  you should be able
> > to specify multiple I/O space (and other) addresses for a single ISA
> > device.  "hayesesp" doesn't provide an ISA bus, so the hierarchy above
> > is ... not really sensible.
> 
> Like recently added `drq2', should we have `port2'?  But it seems that
> it is not the point since you wrote as follows:

We should not have had 'drq2'.  The correct solution to this is to
allow multiple values for certain locators.  'drq2' was done because
the person who did it didn't want to implement the 'right' solution,
or wait for the right solution to be implemented.

Similarly, we should not have a 'port2' locator.  Adding hack upon
hack to the config files (and changing the syntax that users expect to
use N times) simply isn't a good answer to the problem.


> > While i'm at it, it really should be just:
> > 
> > hayesesp0 at isa0 port ....
> > 
> > I.e. no 'com' at all.
> 
> Do you mean that even if the card is operated in ns16x50 compatible
> mode, it should be the device different from `com'?

If the card is to be operated in 16x50-compatible mode, it shouldn't
have any device _other_ than 'com', should it?  If it's to be run in
"extended" mode, hayesesp should drive it.  If it's to be run in
compatible mode, 'com' should drive it.  Really, both 'com' and
'hayesesp' should probably be front-ends to a single back-end driver.
(I don't know how incompatible "extended" mode is; i've never seen one
of these cards, let alone the docs.)


> > ("All this and more could be yours, if the 16x50 driver were ever
> > made into a 'real' front-end/back-end -split driver!")
> 
> Also, do you mean that the chip independent front-end driver + ns16x50
> back-end driver = `com', and the chip independent front-end driver +
> Hayes ESP back-end driver = `hayesesp'?  If `Hayes ESP back-end
> driver' drives the card in native enhanced mode, I think it is ok.
> But is latter case written as follows?  The chip independent front-end
> driver + ns16x50 back-end driver + Hayes ESP ns16x50 compatible mode
> back-end driver (anyway, this result to `hayesesp' not `com'?).

It's too early in the morning for me to parse this...  8-)

What i meant was:

	'com' is a front-end for a generic ns16x50 driver.

If the ESP is "close enough" to a 'com' in extended mode, then
'hayesesp' should be a front-end for that same generic back-end
driver.


cgd