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<== Date ==> <== Thread ==>

Subject: IOSCANPVT
From: Jim Thomas <[email protected]>
To: [email protected]
Date: Tue, 18 Sep 2001 17:11:11 -1000 (HST)
Aloha,

I'm working on Xycom XVME244 device support.  After RTFM'ing, a mailing
list search, and RTFC'ing some existing drivers, I'm confused about how to
do the IOSCANPVT entry.

My take on the processing is that when an I/O "interrupt" routine calls
scanIoRequest() the scan_list in the io_scan_list hiding in IOSCANPVT gets
traversed, and each record in the list is processed.  The drivers I looked
at (xy240, vmic2534, and caenv265) all have a single IOSCANPVT in their
local, per card structure.  Allan's version of the xy240 driver has one
IOSCANPVT per 8 bits (but allocates one per 4 bits).

It appears to me that I would want one IOSCANPVT for each input bit.  That
way only the records referencing that bit would get processed when that bit
changes.  If I have a hundred records looking at one bit on the card and
one record looking at another bit that changes much more often, aren't
those hundred records processed needlessly?

Or does mbbi handling require a common IOSCANPVT ?

Mahalo,
Jim


Replies:
Re: IOSCANPVT Bob Dalesio
Re: IOSCANPVT Marty Kraimer

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