[fprint] FPrint after Windows Usage

[Patrick Marlier]

Hi Pierre,

On 09/09/2015 08:32 PM, Vasily Khoruzhick wrote:
> On Wed, Sep 9, 2015 at 10:35 AM, HERAULT-MARTIN Pierre
> <hickscorp at gmail.com> wrote:
>> Hello list users,
>
> Hi Pierre,
>
>> I'm new to the whole fingerprint thingy. I have purchased a laptop and
>> it offers this fingerprint reader (Some sort of EgisTek device, it is
>> listed as "1c7a:0603 LighTuning Technology Inc.").

Can I ask you what is your laptop?


>> I was wondering if maybe one of you guys have had the same problem than
>> me. I first thought that the problem was randomly appearing, but I
>> noticed a pattern.
>> I sometimes use Windows to play some games, and I think there must be
>> some sort of hardware persistency in the way Windows initializes the
>> device, because every time I reboot to Linux, the fingerprint reader
>> stops working. It basically becomes crazy, and thinks I am scanning my
>> finger over and over again, while i just scanned it once.
>>
>> I found this thread online, but most of the links they suggest are dead:
>> http://www.reactivated.net/fprint_list_archives/2007-November/000159.html
>>
>> Is there anyone who could kindly point me to the correct approach for
>> solving this issue please?
>
> I believe that Windows either downloads new firmware to the device
> and/or changes some register values.
> In first case I don't think we can do anything but resetting the
> device in some way. In latter case it might be useful
> to dump value of registers and compare them with default.

Sounds a good description of potential problem. Thanks Vasily. :)

In latter case, I added a dumpregs program in my development files 
(https://github.com/patrickmarlier/etes603-dev mostly date from 2012 but 
I have just released them). You can try it just after using Windows (do 
not run at all libfprint!) and then later after you scanned your 
fingerprint few times.
Finally diff the 2 files and report it here.

Thanks.
--
Pat