Bug 24109 - Fix incorrect power/idle state for offlined CPUs for SRF/CWF for 6.6
Summary: Fix incorrect power/idle state for offlined CPUs for SRF/CWF for 6.6
Status: NEW
Alias: None
Product: ANCK 6.6 Dev
Classification: ANCK
Component: X86 (show other bugs) X86
Version: unspecified
Hardware: All Linux
: P3-Medium S3-normal
Target Milestone: ---
Assignee: Guanjun
QA Contact: shuming
URL:
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Depends on:
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Reported: 2025-08-21 10:38 UTC by rzhang
Modified: 2025-08-27 14:53 UTC (History)
3 users (show)

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Description rzhang intel_group 2025-08-21 10:38:36 UTC 
Linux puts the offlined CPUs to lowest power/idle state.

The mwait hint used for the offlined CPUs are decoded from CPUID.5. (If the number of sub-states for a given major C-state is nonzero, those sub-states are always represented by consecutive numbers starting from 0)

This no longer works for SRF/GRR/CWF because they support 1 or 2 C6 substates, while the proper mwait hint for them are 0x22/0x23, instead of 0x20/0x21.

As a result, current code set the offlined CPUs to incorrect power/idle state.

Fix the code and use intel_idle driver to provide proper play_dead callback.
Comment 1 小龙 admin 2025-08-27 14:53:32 UTC 
The PR Link: https://gitee.com/anolis/cloud-kernel/pulls/5690