[fprint] elan patch + poc 0x903 and 0x0C03

[Hans de Goede]

Hi,

On 18-06-18 15:03, Bastien Nocera wrote:
> On Mon, 2018-06-18 at 15:01 +0200, Hans de Goede wrote:
>> Hi,
>>
>> On 18-06-18 14:58, Igor Filatov wrote:
>>> I'd like to but I'm worried that people will have bad experience
>>> with these devices (esp. 96x96 ones) and blame libfprint. And I
>>> still haven't had the chance to pull in latest upstream, so...
>>
>> Well ATM people are just blindly adding new USB-ids without
> 
> Who's blindly doing that?

Ok, blindly is not the right term, sorry. What I meant to say
is that they are being submitted with what seems to be
less thorough testing then what has been done by the people
working on the code which is now in Igor's branch.

e.g. the code in Igor's branch reads back the reader
firmware version and basis calibration behavior on that.

IIRC some readers have the same USB-id but a different fw
version and you need to talk slightly different to the device
based on the firmware version. So even if a USB-id added to
the current code works for the submitter it may not work
for all devices with that USB-id.

Which is why I believe it is best to get the changes from
Igor's branch upstream even though these readers still
could use some more work.

>> even getting all the improvements which have been done, so
>> although I agree that these devices need more work
>> (specifically a better match algorithm more suited for
>> low res devices), I still think it would be good to at least
>> get what we have upstream.
> 
> I agree that even if we choose to disable those smaller resolution
> devices, we probably want the code to drive them to be upstreamed.

Agreed.

Regards,

Hans