Linux 7.4 Brings Hibernation Improvement For Meeting Energy Certifications
Linux 7.4 introduces improvements for hibernation power management, aligning with energy certification criteria for various designs.
Intelligence analysis by Qwen 2.5 (3B)
Linux 7.4 updates hibernation power management to meet energy certification standards, addressing a gap in previous behavior.
Linux 7.4 makes sure that when your computer goes to sleep, it also turns off parts of the computer that don't need to work, so it uses less power and can meet special energy rules for some devices.
Analysis
{"heading":"Improving Hibernation Power Management","subheading":"Aligning with S3 Suspend Behavior","content":["The Linux 7.4 update aligns the hibernation power management with the S3 suspend behavior for PCI(e) bridges, ensuring they are powered down during the hibernation process.","Previously, bridges with active children were left in the D0 state during hibernation, preventing meeting energy certification criteria.","This change resolves the issue by using pci_pm_suspend_noirq() to put PCIe bridges with downstream devices into a low-power state (D3hot or D3cold) when the platform allows it."]}
Key points
- Linux 7.4 improves hibernation power management for PCI(e) bridges
- Aligns with S3 suspend behavior to meet energy certification criteria
- Resolves issues with bridges not being powered down during hibernation
This improvement will help ensure that Linux systems can meet energy certification requirements, especially for designs with GPUs.
If the change is not fully implemented or if the platform firmware does not allow turning off the bridges, the energy certification criteria may still not be met.