Fix a problem
If you're having trouble getting the phone to recognize your face:
1.  Go to 
Settings .
2.  Touch Security & location > Face recognition.
3.  Touch Delete face data.
4.  Touch Add face data and follow the onscreen instructions to re-register your face.
Unlock at trusted places
Set up trusted places
To avoid repeatedly unlocking your phone when you are at familiar and trusted locations (like 
home or work), use a 
Smart Lock. You can still manually lock the phone at trusted places when 
needed.
1.  Make sure you have:
• Set a screen lock on the phone.
• Turned on location services.
•
Entered your Home and Work locations in Maps
 (
 > Your places) if desired.
2.  Go to 
Settings .
3.  Touch Security & location > Smart Lock.
If you don't see Smart Lock, try the following:
• Update Google Play services. In the Google Search widget on your home screen, 
search for “Google Play services”, then touch the app to open it.
• Go to Settings > Security & location > Advanced > Trust agents and enable Smart 
Lock.
4.  Unlock your phone, then touch Trusted places.
5.  Set up your places:
• If you added Home or Work locations in Maps, touch the location name and turn it on if 
desired.
• To add a location, touch Add trusted place. Verify your current location to add it, or 
touch 
, type the address to add, and touch Select this location.
Other settings : Security & location : Lock and unlock phone 172