[sane-devel] Canon Lide 200 support is broken in 1.0.27 (Repost from March)

[Alec Bickerton]

On 13.05.2018 06:04, Olaf Meeuwissen wrote:
> Hi Gerhard, Alec, list,
> 
> Alec Bickerton writes:
> 
>> Hi,
>>
>> Could somebody here provide an update for the bug #315752 "Sane 1.0.27 breaks
>> canoscan lide 100"
> 
> @Gerhard> Bug's assigned to you.  Could you take a look?
> 
>> Ubuntu is also tracking the same issue here :
>> https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/1731459
>>
>> As described in the above link, the culprit appears to be patch below, when the
>> change is reverted the issue is resolved.
>>
>> https://alioth.debian.org/plugins/scmgit/cgi-bin/gitweb.cgi?p=sane/sane-backends.git;a=commitdiff;h=bd0b0cd218504868f32962a5558449956c8ce242
>>
>> Can anyone comment?
> 
> I don't know anything about the genesys backend but based on the diff,
> rather than revert, I would try
> 
>   if (dev->model->flags & GENESYS_FLAG_SHADING_REPARK)
>     {
>        if (dev->model->cmd_set->rewind) {
>          status = dev->model->cmd_set->rewind (dev);
>        } else {
>          status = dev->model->cmd_set->slow_back_home (dev, SANE_TRUE);
>        }
>     }
> 
> This should preserve the old behaviour if the device model's command set
> does not have a rewind command.
> 
> Only if this does not fix your issue would I revert.  Also, it may be
> worthwhile to review the device model command set definition for the
> various models.
> 
> Hope this helps,
> --
> Olaf Meeuwissen, LPIC-2            FSF Associate Member since 2004-01-27
>  GnuPG key: F84A2DD9/B3C0 2F47 EA19 64F4 9F13  F43E B8A4 A88A F84A 2DD9
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> 

Thanks,

I've tried the workaround below.
Unfortunately the only I get a clean scan is to revert lines 2075 - 2077 in
genesys.c

They read ...

 if (dev->model->flags & GENESYS_FLAG_SHADING_REPARK &&
dev->model->cmd_set->slow_back_home)
    {
       status = dev->model->cmd_set->slow_back_home (dev, dev->model->flags );
    }

When using your suggestion, I see no difference in the resulting scan. I suspect
that rewind is set incorrectly for my model somewhere. It's been a long time
sine I worked on any C code so I've no idea where to even start looking.

Alec,


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