EgisTec EgisTec0570 - calibration fix (USB 1c7a:0570, 1c7a:0571)

Status: Claimed upstream by the egis0570 driver, but unreliable. Fix MR open.

The in-tree egis0570 driver covers 1c7a:0570 and 1c7a:0571, but calibration is not implemented properly, which shows up as erratic captures and unreliable verification (libfprint issue #418).

What the fix does

libfprint MR !548 ("fix: calibration for egis0570", Saeed/Ali Rk / @saeedark) implements sensor calibration. The author reports the calibration part works as intended - "not perfect but reasonable".

The MR also wants to store calibration data persistently, which needs libfprint's benzea/persistent-data work plus the matching fprintd branch (see MR !368). Without those, calibration is redone rather than saved, which is fine functionally.

How to try it

git clone https://gitlab.freedesktop.org/libfprint/libfprint.git
cd libfprint
git fetch origin merge-requests/548/head:mr-548
git checkout mr-548

Then build per docs/BUILD.md.

Tested on

• The MR author's own hardware; calibration confirmed, persistence not.
• Reports from other 1c7a:0570/0571 owners welcome.

License

Part of libfprint (LGPL-2.1).