Ubuntu
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MSI ez CPU debug led is constantly ON when resume from suspend to ram (S3) state

Asked by Borislav Sapundzhiev

When the PC (running latest distribution or mainline Linux kernel - 5.18.5) wakes up from suspend to ram (S3) state, the motherboard CPU ez debug led light stay solid and does not turning off indicating CPU problem. Otherwise (at first glance) the system works as expected, also there is no ACPI error messages in dmesg. The problem seems to be Linux specific since the issue does not appears on Windows 11.

My question is how this could be diagnosed / fixed (turn light off) ?

Similar problem is reported on Reddit MSI channel: https://www.reddit.com/r/MSI_Gaming/comments/t58dp6/pro_z690a_wifi_ez_debug_cpu_led_turns_red_when/

As additional info one of the processor msr -> MSR_IA32_PERF_CTL (0x199) is restored as 0x1e00 prev value: 0x800 but probably it is not related.

Description: Ubuntu 22.04 LTS
Release: 22.04

BIOS Information
 Vendor: American Megatrends International, LLC.
 Version: 1.10
 Release Date: 03/04/2022

Base Board Information
 Manufacturer: Micro-Star International Co., Ltd.
 Product Name: PRO B660-A DDR4 (MS-7D59)

Processor Information
 Socket Designation: U3E1
 Type: Central Processor
 Family: Core i5
 Manufacturer: Intel(R) Corporation
 Signature: Type 0, Family 6, Model 151, Stepping 5
 Version: 12th Gen Intel(R) Core(TM) i5-12500

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actionparsnip (andrew-woodhead666) said : 		#1

If you are using the mainline PPA kernel then I suggest you report a bug with that.

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