Long Delay before instructed to swype

[RJdaMoD]

Hi, thanks for your driver, it makes my fp-reader of my dell work at last. But i have one issue: When i try to login, sudo, gksudo or use the demo, it takes up to 3 seconds before the "swype your finger"-message appears. I did a quick debug on your code, but can't tell if its there or in the rest of libfprint. Can you please check? Thanks

[ars3niy]

Hello,

First of all, I'm sorry for such a late reply. I just completely forgot about checking out feedback here on github.

Thank you for testing the driver, I'm glad that it's useful. I have just added timestamps to debug output. So if you still don't mind debugging this, you can pull the latest update, recompile with debug logging (by passing --enable-debug-log to configure) and run the demo redirecting error output to a file (like this: fprint_demo 2>debug.log). By looking at that debug log, it should be possible to tell exactly where does the delay happen.

[ars3niy]

There used to be some lengthy initialization sequence (which took about 1 second for me) that happened every time while acquiring the image. It could be that in your case it was longer.

With the last changes, it's instead done when opening the device. For fprint_demo it means that delay will now happen once during startup rather than every time before enrolling/verifying. I'm not sure how this will affect login and sudo, though.