Re: [BUG] s2idle: unrecoverable sleep on ThinkPad P16s Gen 4 AMD, (Strix Point) when more than 16 logical CPUs are online

[Mario Limonciello <mario.limonciello@amd.com>]

On 9/23/26 15:48, Fourhundred Thecat wrote:
> the bug reproduces on 7.3-rc4.
> 
> Built 7.3-rc4 from the torvalds snapshot, migrated my 6.18.51 config 
> with make olddefconfig, IOMMU enabled, all 24 CPUs online, no IOMMU boot 
> parameters. Same result: the machine suspends and never wakes, forced 
> power off required.
> 
> Both attempts recorded by the same script, neither produced a resume block:
> 
>    === 2026-09-23T22:15:02 BEFORE
>    cmdline:     (6.18.51, no iommu parameters)
>    cpus online: 0-23
>    iommu:       ivhd0
>    ff_rt_clk:   0
>    S0ix Entry Time: 0 / Exit Time: 0 / Residency Time: 0
>    suspending with +30s alarm
> 
>    === 2026-09-23T22:39:06 BEFORE
>    cmdline:     (7.3.0-rc4, no iommu parameters)
>    cpus online: 0-23
>    iommu:       ivhd0
>    ff_rt_clk:   0
>    S0ix Entry Time: 0 / Exit Time: 0 / Residency Time: 0
>    suspending with +30s alarm
> 
> Both used a programmed RTC wakealarm at +30s and were left untouched for 
> several minutes.
> 
> Relevant details of the 7.3-rc4 build, so this is not a configuration 
> difference:
> 
>    CONFIG_AMD_IOMMU=y, CONFIG_IOMMU_PT=y, CONFIG_IOMMU_PT_AMDV1=y
>    CONFIG_NR_CPUS=24, CONFIG_MODULES not set
>    CONFIG_DEBUG_FS=y, CONFIG_PM_DEBUG=y, CONFIG_DYNAMIC_DEBUG=y
>    CONFIG_AMD_MP2_STB=y, CONFIG_X86_MSR=y, CONFIG_DMIID=y
>    CONFIG_LOG_BUF_SHIFT=20, CONFIG_RANDSTRUCT_NONE=y
>    kernel is not tainted, builds with zero warnings
> 
> Only 243 config lines differ between my 6.18.51 and 7.3-rc4 configs. 
> Both commits you pointed me at are present in 7.3-rc4: rtc-cmos uses 
> platform_get_irq_optional(), and iommu/amd carries the "No ACPI device 
> matched UID" check. As on 6.18, that FW_BUG message does not appear here 
> either.
> 
> Two things worth noting about the 7.3 build specifically. The new IOMMU 
> page table layer is in use (CONFIG_IOMMU_PT / IOMMU_PT_AMDV1 replacing 
> CONFIG_IOMMU_IO_PGTABLE), so that rework does not change the outcome. 
> And AMD_PMF and DRM_ACCEL_AMDXDNA are not compiled into either kernel - 
> DRM_ACCEL and AMD_SFH_HID are both off in my config - so neither driver 
> is involved in any of these results at all, which is a stronger 
> statement than the initcall_blacklist tests I reported earlier.
> 
> Where that leaves things. With the IOMMU enabled and all 24 CPUs, on 
> both 6.18.51 and 7.3-rc4:
> 
>    lid switch, internal keyboard, power button, USB mouse with wakeup
>    armed, and a programmed ACPI RTC alarm        all fail to wake
> 
>    intremap=off, iommu=pt, amd_iommu_intr=legacy  all still hang
>    pm_test freezer / devices / platform           all pass
>    PC6 and CC6 enabled per amd-s2idle             yes
> 
>    amd_iommu=off                                  wakes normally,
>                                                   Last S0i3 Status Success,
>                                                   13.3s residency,
>                                                   pm_wakeup_irq 9
> 
> Since it fails identically on 6.18 and 7.3 there is no working kernel 
> version to bisect against. The only variable that changes the outcome is 
> whether the IOMMU is enabled, and secondarily whether more than 16 CPUs 
> are brought up at boot.

To me this still feels like a BIOS bug.  I wouldn't discount the 
possibility that think-lmi didn't apply a setting properly or something 
like that.

Can you please try to manually go into your BIOS and reset BIOS default 
settings?  Does it reproduce with IOMMU left on?