Hi, Fedora Workstation WG is tracking the following issue: Support for hibernation? https://pagure.io/fedora-workstation/issue/121 ACPI power states decoder ring [1] S0 normal powered on state, S0 low power idle, freeze, s2idle, connected/modern standby, power nap S1 standby, power-on suspend, shallow S2 not used on linux S3 suspend, suspend to RAM, S2RAM, sleep, deep S4 soft off, used for hibernate/suspend to disk and implies firmware coordination S5 power off, used for hibernate/suspend to disk Summary of the issues: - Hibernation image and swap (paging) share the swap device. There's no kernel support to separate them. With a shared swap partition, there's no guarantee there will be enough contiguous free space (this is a requirement) to write out the hibernation image. - A swap device sized at 1:1 with RAM, and any appreciable use of swap, will thwart the creation of a hibernation image. This is discovered at hibernation image creation time. - A swap device sized at 2:1 with RAM might be quite a lot more reliable, but it's still not a guarantee. And already the swap partition is considered too big.[2] And we're considering dropping it by default in Fedora 33 in favor of swap-on-ZRAM. [3] - Hibernation is getting very little attention by hardware vendors and Microsoft. - For 5+ years the emphasis has been on S0 low power idle (a.k.a. freeze, standby, s2idle, S2I, modern standby, and power nap), and faster boots. Hibernation is intended as a last resort fallback when the battery charge becomes low. - Microsoft's hardware certification mandates UEFI Secure Boot by default since Windows 8 (2012). It's reasonable to estimate this is the vast majority of present and future hardware. - Linux kernel enforces hibernation lockdown (among other things), on UEFI systems with Secure Boot enabled. - S3 (a.k.a. suspend, suspend-to-RAM, S2RAM, STR, sleep, deep) is widely available hardware and linux support wise; but the gotcha has always been wake from suspend and device reactivation, including graphics. There are lots of firmware, ACPI, and kernel bugs, and regressions, and it's make/model/version specific. - Lately, since ~2018 [4], linux is catching up, with more effort being put into S0 low power idle (called s2idle on linux and either connected standby or modern standby on Windows, and power nap on macOS). It's all done in software, and ostensibly has no firmware or ACPI dependencies, so it can be done on any platform.[4] - uswsusp: I can't find any recent upstream information on it. [6] It's not packaged in Fedora. I see no evidence of image signing capability. If it could work around kernel Secure Boot lockdown, I think most any reasonable person would consider that a security vulnerability. - Fedora kernel team has said resource constraints means hibernation is not a priority, i.e. it's best effort, and can't practically be release blocking. There's prior, Fedora specific, kernel, systemd, and GNOME discussion in these threads. [7] I'll start a separate thread for questions and discussion. [1] https://www.kernel.org/doc/Documentation/power/states.txt https://www.kernel.org/doc/html/v4.19/admin-guide/pm/sleep-states.html [2] https://pagure.io/fedora-workstation/issue/120 [3] https://pagure.io/fedora-workstation/issue/127 [4] https://lwn.net/Articles/762132/ [5] https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/platform-design-for-modern-standby [6] http://suspend.sourceforge.net/ https://wiki.archlinux.org/index.php/Uswsusp [7] https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx/message/EWYAXHJRCT6FLA7D2G3TLTPDV2OXHPHF/ https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx/message/TLTA6HAYJWQYHV3ZHFXUIXM4IJVWBEJJ/ https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx/message/DHBBPY2PGAJRW2PINXVWNAFSZY2WDI7Q/ -- Chris Murphy _______________________________________________ desktop mailing list -- desktop@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to desktop-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/desktop@xxxxxxxxxxxxxxxxxxxxxxx
