Proximity sensor ON in Lock Screen - IR LED visibly strobes

[romanempire]

Firmware: 47.1.A.2.324 (Customized US)

I noticed this on XZ1 first, but XZ1 Compact also has this issue.

If you have a PIN set, go to a sufficiently dark room and press the power button to show the PIN pad. You should see an IR LED light up on the right side of the speaker grill.

Once you enter the PIN, the LED turns off.

Logs show that pSensor gets enabled and reacts to me covering the sensor:

W/qti_sensors_hal(909): Thresh::processInd: Proximity Status 0.0, A/D 0x006c( 108)
D/TransmitPower(2238): PSensorObserver:onPSensorStateChanged() : isNear = false
D/TransmitPower(2238): PSensorObserver:onPSensorStateChanged() : isNear = false
W/qti_sensors_hal(909): Thresh::processInd: Proximity Status 1.0, A/D 0x01a5( 421)
W/qti_sensors_hal(909): Thresh::processInd: Proximity Status 0.0, A/D 0x00c6( 198)

Does anybody else see this? Does anybody know why this is happening? The logs don't show that camera gets enabled (e.g. for face unlock, if it was implemented), and the phone does not change its behavior whether the sensor is covered or not.

[romanempire · Accepted solution]

Wow, I should have tested it more. This thing prevents screen intereaction if it detects an object in close proximity (e.g. in a pocket).

[Snapples]

That still leaves the question if you can actually turn that off.

[romanempire]

Not sure why one would want to, uness the sensor service gets stuck (but that is another issue altogether). During a month with XZ1* devices I had no issues related to the proximity sensor.

[Snapples]

Well, it's basically useless to me since I exclusively unlock with the power button.
Plus it drains battery. May be almost nothing, may be not a lot, but it does.

[romanempire]

I have a PIN, so avoiding accidental pin entry is quite useful. I have also been able to do an unattended factory reset of my Nexus 5 while biking, so I think this is a good feature in XZ1.

However, does XZ1/Compact enable proximity sensor even when PIN or password is not set up?