RE: [hpoj-devel] SMP patches?

[PASCHAL,DAVID (HP-Roseville,ex1) <dav...@hp...>]

Robert G. Brown wrote:
> Searching the hpoj-devel list archives, I learned that there 
> has been a
> patch proposed for smp systems because of deadlock issues 
> resulting from
> a non-smp-safe bottom half handler.  I looked for the patch as best I
> could on the website, but found nothing.
Hi, Robert.  Please see http://hpoj.sourceforge.net/todo.shtml.  You can use
the patch against 0.6, unless you want to deal with downloading from CVS and
then patching that.

> I have a bit of kernel module and smp expertise myself (at 
> least enough
> to know what a "bottom half handler" is:-) and can possibly even help
> intelligently in the event that the patch doesn't fix my problem(s).
All input is welcome.  :-)  If nothing else perhaps you can review the
changes to ieee12844pp.c and ieee12844.c (particularly the functions
mlc_sendmsg and mlc_recvmsg in the latter file) and let us know if you see
any problems.

> Now regarding "perfectly".  I'm using the cdj550 filter, but 
> results on
> photographs leave a great deal to be desired.  I feel like I'm getting
> at most a tiny fraction of the printer's potential 
> resolution.
Yes, unfortunately this is the case at the moment, but there is work being
done within HP to develop an open-source driver to take advantage of the
newer inkjets (http://www.linux.hp.com/open_letter.html).

If you don't mind patching and rebuilding ghostscript, then you might
benefit some from this DeskJet 970C driver, which should also work on the
OfficeJet G and K series:

http://www.linuxprinting.org/show_driver.cgi?driver=cdj970
http://www.harsch.net/Ghostscript/ghostscript.html

The second site is in German.  Babelfish
(http://www.babelfish.altavista.com)
gives a fairly decent translation.  If you try this out I would be
interested to hear about your impression/experience with it.

> Again diligently searching the web I see that there is an 
> "hpdj" driver
> for postscript that is being developed that speaks pcl3+ and 
> that might
> produce superior results on the G55 or other OfficeJets.
The hpdj driver is for the original DeskJet and DeskJet Plus.  Supposedly it
produces better text than cdj550, but it appears to be black and white only,
not color.

David