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:
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,