[sane-devel] Canon LiDE 20 vertical lines

[Gerhard Jaeger]

Hi Monty,

On Friday 05 August 2005 17:12, Monty wrote:
> On Fri, Aug 05, 2005 at 10:10:04AM +0200, Udo Lütkemeier wrote:
> > Hi Gerhard,
> >
> > On Fri, 05.08.2005 07:59 +0200, Gerhard Jaeger wrote:
> > > these are the lines that should not appear :(
> > > I've done some tests here with a LiDE30 and there were no lines, then I
> > > connected the N670 (which should be the same device as the LiDE20) and
> > > I see also these damned lines - I don't know currently where the
> > > problem is - I have to do some more testing.
> >
> > I hope, you find the problem/error and can solve it in the next
> > releases.
> >
> > Please let me and the LiDE20/N670 user know here, when the problem is
> > located or solved.
>
> I have a LiDE20 and was the person who originally 'completed' the
> driver support.  Vertical lines are indeed a fine calibration problem
> and after I fixed the original nonfunctional code, fine calibration
> has been broken again several times.  Apparently it has been broken
> yet again; I got tired of it breaking all the time and nailed my
> package system to hold the installed version at 1.0.13, which I knew
> to work properly.

I really appreciate your work and was happy that someone fixed this
issue at least for the LiDE20, but I could not accept this: "broken
several times..." - If the code is broken before a new SANE version
will be released, I'd like to have some feedback not any complaints
AFTER code-freeze, that's the way the show works. 

> Honestly, I don't have the time to fix this for the third time....  Is
> there any kind of regression testing going on?  I know it's hard to
> maintain a driver for diverse, low-end hardware families, OTOH, this
> is getting a little ridiculous.  LiDE fine cal is broken more often
> than it's working.  Having one driver trying to serve fifty different
> models across a family of ten related chips is unworkable when changes
> to any one model break ten others that can't even be tested because
> the author doesn't own the hardware to do the testing.

That's indeed more or less impossible. I own the N670 which should be
more or less the same as the LiDE20, but I could not test every single
device before a release takes place - I need feedback from others.

> I'll put up the last LiDE20 driver (which works: I'm still using it) I
> contributed as soon as the machine it's on is on the Net again (just
> moved to a new house, IT there is in disarray).

So you're still working with SANE-1.0.13? Is 1.0.14 also broken? In the
end the differences to 1.0.13 are not that large. I'll submit a patch
probably this evening and you're welcome to cross-check. What about the
pictures from 1.0.13? Aren't those too dark? 

As I already said criticism is a good thing, as long as it is constructive!

Ciao,
Gerhard