answered
2017-08-10 10:20:23 +0200
Some expectations and speculation:
- "I shut down the phone" (assumption: charger cable is not connected at this stage)
- "plug in the usb cable to charge the device" -> the phone should boot up to so called "act dead" mode
- "the device sometimes vibrates shoses the jolla logo" -> depending on device, more or less expected
- "goes black" -> what should happen is that the act dead charging ui comes visible
- "vibrates and shows the logo again" -> rebooted before bootup to act dead finished?
- "boots up" -> due to the extra reboot at (5), boot reason is no longer "charger inserted" -> boots to ui
- "shut down the phone" -> shutdown while cable connected -> power on due to charger
- "show the charging logo" -> this time the bootup to act dead mode succeeded
Now the interesting part is what happens around (4). If charging does not commence (within a minute or so), the device should attempt to shutdown in this state. But even then there should be enough time to show the charging ui (showing picture of unconnected cable).
I managed to reproduce something similar fairly reliably (shutdown while having charger connected, wait for the shutdown picture to show up and go away, then unplug the charger, wait for shutdown to finish and some more, then plug the charger). On a quick glance it looks like something goes wrong really early: The boot logo is shown by boot loader - twice in this case, and when the system gets so far that journal gets a chance to collect logging, the power on reason has been lost from kernel point of view too -> boot up to ui gets chosen.
Hopefully - whatever is causing this - it is related to one internal reboot related bug that we have been unable to reproduce in reliable manner so far...
EDIT:
Turns out it is reproducible as long as you do not attempt to take traces of early boot i.e. trying to find clues where the problem is also makes the problem not appear anymore. Due to these debugging difficulties and relatively benign nature of the problem -> is not actively investigated anymore.
I have not seen that, but I charge on a timeswitch overnight so it might boot up and I would be unaware of it. But in the morning I pull out the USB plug (power still on) and, after a while, it vibrates, displays 'One moment...' and then turns off. This hasn't changed in ...23 or ...24.
Does yours do that?
DaveRo ( 2017-08-07 12:59:37 +0200 )editI can confirm this. I have seen this issue once but normally I do not shut off my phone, not even during charging. I could take a second look if it is still present.
MoritzJT ( 2017-08-07 16:17:17 +0200 )editI've seen similar problem. Thought it was something with my battery as it had started to oxidize and malfunction quite heavily on a regular basis. However, this made it really difficult to start charging my JollaC when battery was not charged. I then also noticed that my usb cable that I used to charge it with had worn out, so I replaced it.
However, I cannot reproduce it with new battery and new cable on my JollaC.
pfbach ( 2017-08-07 19:11:34 +0200 )editUpdate: I switched my SIM-card today, and shut down my Jolla C completely. When I re-inserted the battery, attached the back cover and plugged in the charger it vibrated twice and OS was booted up. I didn't expect this, as I didn't push the power button.
pfbach ( 2017-08-10 01:28:01 +0200 )edit@:pfbach : Exactly that behaviour.
1. I shut Jolla down without charger wire (USB Cable). 2. plug usb cable in Jolla than 3. Plug Charger in wall socket. 4. Jolla vibrates show logo 5. Screen goes black 6. Jolla virbate again and show logo and boot up.
I shot down manually with button or menu. After that Jolla goes into charging mode. Very annoying
monkeyisland ( 2017-08-11 09:20:12 +0200 )edit