Re: [hpoj-devel] xojpanel

[Joe P. <joe...@sn...>]

On Saturday 02 December 2000 04:40, David Paschal wrote:

> > Hi, Joe.
>
> joe...@sn... said:
> > There is another problem with either xojpanel or the low-level code.
> > Sometimes xojpanel fails to start on the first try. This message is
> > displayed  at the command line:
> >
> > "Error 0 (system error 100) in file mlccon.c, line 280: Unexpected
> > error,  please post a bug report to hpo...@bs..."
>
> I will fix that e-mail address.
>
> > If I try to start it a second time, xojpanel usually starts and runs
> > with no  problems that I can see.
>
> I'm not sure what the problem here is, but the problem must be in the
> low-level driver code.  Do you see any error messages in syslog
> (/var/log/messages)?  You could also try using the "debug=1" parameter when
> loading ieee12844pp.o, and maybe from that I can tell where it's going
> wrong. Could you elaborate on the circumstances in which this happens?  For
> example, does it only happen the first time after you load the drivers, or
> does it happen after you power-cycle the peripheral, etc.?

Lately the line number reported in the error message has been 263, but that 
doesn't matter very much now. I'm reasonably certain I found what was causing 
the problem. In /var/log/messages the OfficeJet is reported as being on an 
EPP port rather than an ECP, which I thought it was. After I removed the 
ieee12844pp module and reinserted it with the usenibble=1 option, xojpanel 
starts every time. I wrote a shell script that would repeatedly start and 
then kill xojpanel 6 seconds later. It's been through 1000 startups so far 
without any failures. Previously, one try in 15 starts would fail (rough 
average).

I'll see what happens after I change the port type to ECP on the IO card the 
OfficeJet is connected to. 
 

> Attached is a patch containing some changes I made.  The second change adds
> an explanation if xojpanel dies because the peripheral doesn't support LCD
> readback.  The first change changes the poll rate from once to four times
> per second, which greatly improved the response when I was scrolling
> through menus really fast.  However, it's probably not worth actually
> putting in, because I expect most people wouldn't need this level of
> responsiveness given the extra overhead it introduces, and IIRC you
> previously indicated some reason (debugging?) why you didn't want it to
> poll more than once per second anyway.
>

The patch installed ok, but it gave two error messages:
patch unexpectedly ends in middle of line
patch unexpectedly ends in middle of line

xojpanel compiles runs fine with the patch.

Early in development, the printer poll timer controlled scroll speed as well, 
so to cut down on unnecessary console output during testing, I set it as high 
as 3000ms (if I remember correctly). Now that the timers are separate, that 
reason is gone. The poll timer can be set lower than 1000ms. Are there any 
network delay issues to consider in setting the timer? For instance, if an 
lcd message is changing in the printer, but it's being polled too often, the 
wrong message might get to xojpanel first. Could this happen?

Overhead doesn't seem to be a big problem with xojpanel. It seems to use a 
lot of memory, but little processor time. top -p says that most of the time 
its CPU usage is 0.0%. The timer is set at 500ms for now, though.


> I'm glad you added the license statement at the top of the files, but you
> might want to add a copyright message, similar to what I did in the ptal
> and ieee12844 directories.  If you do this then it would be proper to also
> include a copyright for the original author, which I think was Andreas
> Fester.  (Is this correct, Andreas?  And what copyright year should be
> given for you?)

I'll put a copyright notice in, with credit for anyone who contributed to the 
remaining parts of the original xojpanel, if the contributors can be 
identified. If not, I'll give generic credit. It might be important to know 
the origin of the name 'xojpanel'. Andreas' response should be helpful. 

>
> When should I start putting this into CVS?  Once I do, then it would be
> preferable for additional changes to be made available as patches to
> hpoj-devel, even if you continue to provide a downloadable package on your
> website.
>
> Am I correct in assuming that the only file I should remove from CVS is
> lcd.bmp?  For the new files you provide, should I include
> CHANGES-xojpanel_jsp (possibly renamed to just "CHANGES")?  It might be
> easier to let the CVS checkin comments serve as the changelog.  What about
> xojpanel.kdelnk (maybe?) and .directory (probably not)?
>
> David

Hopefully, the copyright issue will be solved soon, so waiting a day or so 
before committing the new xojpanel code to CVS will probably make one patch 
unnecessary. 

Handle the changelog whichever way you think is best.

You won't need .directory for anything. I probably should have deleted that. 
lcd.bmp is no longer used or even very usable, due to a size difference. You 
can leave both of them out.

A KDE user could copy xojpanel.kdelnk to his/her desktop for a quick way to 
start the app. Many users may prefer to create their own launchers, but some 
don't know how, or don't want to go to the trouble. The addition of a GNOME 
launcher might be nice later on. I have only an older version of GNOME and 
haven't used it in a while, so I wasn't that interested in making one right 
away.


-- 
Joe