ubuntu-phone team mailing list archive

[sturmflut <sturmflut@xxxxxxxxxxxxxx>]

Hi all,

I think I've tracked down the "slow wakeup" to in-kernel
power-management in
https://bugs.launchpad.net/ubuntu/+source/unity8/+bug/1421455 .
Basically powerd instructs the kernel to wake up by writing the string
"on" to /sys/power/state and something inside the kernel takes much
longer than expected. powerd blocks on this write() for about half a
second and only then turns on the screen, which takes a bit of time as
well, so the total time from the power button press to a visible image
on the screen is slightly more than one second on my device.

Sadly I don't know how to debug the kernel issue.

kind regards,
Simon



On 16.04.2015 18:54, Ari Börde Kröyer wrote:
> Hi
> 
> Here is an issue I have had since I installed Ubuntu on my Nexus 4 in
> October 2014, and now it has appeared on my Bq Aquaris e4.5
> approximately 3 weeks after I got the phone.
> 
> Often, but not always, when pushing the power button to make the screen
> wake up, nothing happens. After waiting a few seconds, I push the button
> again and the screen wakes up for a fraction of a second and then turns
> off. The behavior suggests that the second time the button was pushed it
> was registered as a "switch off screen" command. This can repeat itself
> a few times. Usually, I have to push the button slightly harder/more
> decisively (perhaps a hint longer) in order for the screen to wake up
> and stay on. Very annoying.
> 
> I wonder if others have experienced this issue?
> 
> I originally wrote it off to wear on my somewhat old Nexus 4 handset,
> but since it appeared on my brand new Bq Aquaris, I wish to report this
> as a bug. Problem: I don't know what it can be related to, so I don't
> know where to register this bug. Can someone give me a link?
> 
> Thanks,
> Ari
>