Improving Linux battery life, enabling PSR by default, testers wanted

02-01 17:52

Hi All,

As you've probably read already I'm working on improving Linux laptop battery live , previously I've talked about enabling SATA link powermanagement by default . This is now enabled in rawhide / Fedora 28 since January 1st and so far no issues have been reported. This is really good news as this leads to significantly better idle power consumption (1 - 1.5W lower) on laptops with sata disks. Fedora 28 will also enable HDA codec autosuspend and autosuspend for USB Bluetooth controllers, for another (aprox) 0.8W gain.

But we're not done yet, testing on a Lenovo T440s and X240 has shown that enabling Panel Self Refresh (PSR) by setting i915.enable_psr=1 saves another 0.5W. Enabling this on all machines has been tried in the past and it causes problems on some machines. So we will likely need either a blacklist or whitelist for this. I'm leaning towards a whitelist to avoid regressions, but if there are say only 10-20 models which don't work with it a blacklist makes more sense. So the most important thing to do right now is gather more data, hence this blog post.

So I would like to ask everyone who runs Linux on their laptop (with a recent-ish kernel) to test this and gather some data for me:

  1. Get a baseline powerconsumption measurement, install powertop ("sudo dnf install powertop" on Fedora), then close all your apps except for 1 terminal, maximimze that terminal and run "sudo powertop". Now wait 5 minutes, on some laptops the power measurement is a moving average so this is necessary to get a reliable reading. Now look at the power consumption shown (e.g. 7.95W), watch it for a couple of refreshes as it sometimes spikes when something wakes up to do some work, write down the lowest value you see, this is our base value for your laptops power consumption, write this down.
  2. Add "i915.enable_psr=1" to your kernel cmdline and reboot, check that the LCD panel still works, try suspend/resume and blanking the screen (by e.g. locking it under GNOME3) still work.
  3. Measure idle powerconsumption again as described under 1. Make sure you use the same LCD brightness setting as before, write down the new value
  4. Dump your LCD panels edid, run "cat /sys/class/drm/card0-eDP-1/edid > panel-edid"
  5. Send me a mail at hdegoede@redhat.com with the following in there:
  • Report of success or bad side effects
  • The idle powerconsumption before and after the changes
  • The brand and model of your laptop
  • The "panel-edid" file attached
  • The output of the following commands:
  • cat /proc/cpuinfo | grep "model name"
  • cat /sys/class/dmi/id/modalias

Once I've info from enough models hopefully I can come up with some way for us to enable PSR be default, or at least build a whitelist with popular laptop models and enable it there.

Thanks & Regards,

Hans

Tags:fedora, kernel , xorg

原文链接:https://hansdegoede.livejournal.com/18653.html?utm_source=tuicool&utm_medium=referral
标签: Linux
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