Re: [PARPORT] ppscsi/epst mode question(slow scanning w/ hp5200C


grant@torque.net
Fri, 25 Jun 1999 06:43:39 -0400 (EDT)


> If I put the port into 'static' EPP mode (i.e. you
> can change all you want in base+whatever and it won't change the chip's
> mode) epst runs in PS/2 mode which, as stated above would be expected.

Why ? EPST uses the EPP registers, so they should respond.

You mentioned EPP 1.7 v 1.9 - did you try both ? This setting is
irrelevant to the software, but can make a difference to the "on the
wire" handshaking. I haven't heard of reports of it mattering with
Shuttle adapters, but some others are quite sensitive to that setting.

Did you actually send me the dmesg log generated when you load EPST
with verbose=1 ? I don't recall seeing it. We may be looking for the
wrong things here.

> I can change the chip
> into any mode I want, but installing epst changes the chip back to some
> other mode. I havn't really looked at how epst does what it does.

Well, EPST is _not_ doing anything that should have that effect. It
does not touch the configuration registers or the extended registers.

The running mode is selected by running data integrity tests in each
of the possible protocols and looking for errors. If EPP mode is not
working with the chip, there will be errors in these tests, and the mode
will not be accepted. The verbose=1 messages will tell me which tests
are actually failing.

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Grant R. Guenther grant@torque.net
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This archive was generated by hypermail 2.0b3 on Fri 25 Jun 1999 - 06:46:57 EDT