[fprint] aes1610 patch

[Daniel Drake]

> Yes, this is for that reason. I think I'll move it to the loop sooner or 
> later. For now, I leave it here as I'm not sure about the number of 
> strips we should capture between every gain adjustement. I'll fix it 
> with gain stuff. I think.

Looking at the code closer, I can see why you've done it this way: you 
do 2 initial captures before sending strip_scan_reqs. Maybe these 
initial 2 scans are used by the windows driver for gain calibration and 
should be discarded from the resultant image...

>>> +    // img->height must be >= 12 (if not, we get seg fault)
>>> +    // img->height = 8 when we don't move the finger on the sensor
>>> +    // We set it to 12 to avoid a crash.
>>> +    if (img->height < 12)
>>> +        img->height = 12;
>>> +   
>>
>> Why 12? Where does the segfault happen?
> 12 because this is the minimum to avoid the segfault. This is a dirty 
> fix! The segfault happens on line 132 of libfprint/nbis/mindtct/maps.c.

OK. We should fix this properly, so I left this part out of the patch. I 
wonder if NBIS simply fails on tiny images. If you think that sounds 
like a possible explanation, could you please file a bug for this at
http://www.reactivated.net/fprint/bugs/


The rest of the patch is committed locally.

Thanks!
Daniel