[sane-devel] Canon LiDe 210 Genesys backend gone wrong

[Jay Christnach]

On 06/28/2012 09:25 PM, stef wrote:
> Le 28/06/2012 13:59, Jay Christnach a écrit :
>>> Hello,
>>>
>>>     thanks for all these data. I have uploaded at 
>>> http://dl.free.fr/gEzUYJkHX a small 'gl124' unit test program. It 
>>> does an uncorrected color scan at 150 dpi. It is a fully static 32 
>>> binary using libusb-1.0.9 . Put it in a directory, copy your 
>>> genesys.conf file in the same directory then run it. You should see 
>>> the lamp switch on. I'm curious to know how it behaves in the 
>>> "buggy" hardware combination.
>>>
>>> Regards,
>>>      Stef
>     OK,
>
>     now here's the same test program compiled against legacy libusb 
> 0.1 (and not through the compat libusb-1.0). If it still doesn't light 
> on the lamp, I think we can rule out a libusb problem:
>
> http://dl.free.fr/rm.pl?h=reyVJTLYp&i=48660014&s=XdEvMMX5NTGQlxGZp3zmhq6vZSkoY4FE 
>
>
>
> Regards,
>     Stef
>
>
Hello again,

I have some news:

The problem is intermittent! Sometimes after rebooting it works again, 
but then eventually fails again.

(These days I'm refoaming loudspeakers in my lab and I use a big power 
amp to test with a 2 Hz signal if the cone is centered. The amp 
sometimes triggers the circuit breaker while switching on, so that power 
is lost and I have to restart my computer. Usually I let it run all the 
time.)

By chance I tested your statically linked test program again and found 
it worked this time! I already suspected that the problem would be 
intermittent, but I was not sure when and how.

So be assured now, that there is no software problem. It is linked to 
the fact that I use some usb port to connect my smartphone. I did some 
testing when nothing but the scanner was connected and it didn't work. 
For the moment it works and I tried connecting the phone while scanning. 
The LEDs immediately went dark when I connected the plug. Unlugging it, 
it worked again.

I now also observed a few scans where the light went dark in the middle 
of the scan without the phone being connected.

I will try with different ports for my devices or maybe a powered hub 
and the problem should be solved. So Armin Stebich was right in that 
matter that it is a power over USB problem.

So sorry for bothering you and many thanks for your help. I'm pretty 
convinced that this issue is now solved.

Best greetings