The laptop suspends and resumes pretty much faultlessly, very very occasionally it doesn’t which seems to be related to having installed a significant number of patches.
My problem is this: when running on batteries, resuming from sleep results in slow operation and neither of the CPU cores will run at full speed, so the laptop feels sluggish.
If I plug the charger in before opening the screen to resume, it runs fine at the regular speed. If I subsequently unplug the charger, it continues to run at that speed, albeit with KDE switching to a battery mode.
This problem has persisted across the standard kernel, as well as one from tumbleweed/factory, currently 3.17.1-53.gd944251-desktop.
I am using an official Dell charger, and the laptop is happy with that, charging the four cell battery at a decent rate (1% per minute), and run time on batteries is pretty good with five hours screen on time.
I would be grateful for any ideas as to what to do because apart from this annoyance, I am delighted with my laptop.
thanks
Paul
I’ve not solved the problem. It means that if the laptop is asleep and I want to use it without the charger connected, I have to open the screen to wake it up before unplugging, otherwise the cores won’t run above 400MHz. Sometimes I forget and the solution is to close the screen to make it sleep, wait till power light “breathes” slowly, then connect power, then wake it up and unplug it
I’ve tried different kernels - but am still on 13.1, using Tumbleweed packages.
I’ve got the kernel option “processor.ignore_ppc=1” set, which I used to have to use when I had a Dell E6420 and used a small/portable underpowered charger, otherwise the BIOS would force underclocking.
It doesn’t appear to affect Windows (7 pro 64 bit).
On 2015-01-18 17:06, speculatrix wrote:
>
> I’ve not solved the problem. It means that if the laptop is asleep and I
> want to use it without the charger connected,
Are you using laptop-mode-tools? Try using them if not.
It seems that your machine goes into a mode to conserve battery when it
awakes from suspend. It may not be the kernel which does this. I think
it might even be the desktop, so you might try another one.
–
Cheers / Saludos,
Carlos E. R.
(from 13.1 x86_64 “Bottle” at Telcontar)
