Fedora 28 Will Hopefully Enable Intel PSR To Further Conserve Laptop Power
Red Hat developer Hans de Goede has recently been on a mission to improve Linux battery life on Fedora. Now that SATA link power management is better handled and other tweaks, his latest target is on getting Intel's Panel Self Refresh (PSR) support enabled.
Panel Self Refresh has been available for years but isn't enabled by default since for some hardware it can run into issues. PSR is part of the Embedded DisplayPort standard (eDP) for conserving power by being able to refresh the screen pixels directly when the screen's contents is not changing. PSR is supported by laptops/ultrabooks with eDP-based panels for the past several years, but again some quirky hardware can have issues with this functionality enabled.
Hans is looking for users to try out Panel Self Refresh on their systems to see if it works out. Enabling Panel Self Refresh on any semi-recent system can be done by booting with i915.enable_psr=1 as a kernel command-line parameter. For more information on the feedback Hans is seeking, see his blog post.
Depending upon the PSR results, he's hoping to incorporate a blacklist or whitelist for automatically enabling Panel Self Refresh where safe for the next Fedora release. PSR can cut down the Linux power use by another half Watt or so.