Re: AMD AHCI + Samsung 870 QVO STANDBY IMMEDIATE time out

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

++ AMD guys

On 9/14/26 11:18, Niklas Cassel wrote:
> Hello Mario,
> 
> 
> Perhaps you, or someone at AMD could help us with this:
> https://bugzilla.kernel.org/show_bug.cgi?id=221986
> 
> 
> Is seems that a user is having issues with:
> 
> 12:00.0 SATA controller [0106]: Advanced Micro Devices, Inc.
> 	[AMD] 600 Series Chipset SATA Controller [1022:43f6] (rev 01)
> 
> together with:
> 
> Samsung SSD 870 QVO 8TB
> 
> 
> when being issued command STANDBY IMMEDIATE (E0h) during system suspend.
> 
> The command never receives a completion.
> 
> 
> It seems that this is only a problem when "med_power_with_dipm" is enabled.
> 
> Apparently, when using "max_performance" the drives do complete the
> STANDBY IMMEDIATE (E0h) command successfully.
> 
>  From looking at the AHCI specification, the HBA should automatically wake
> the drive when a new command is issued via PxCI.
> 
> 
> 
> The user did point out that these Samsung drives are quirked with:
> ATA_QUIRK_NO_LPM_ON_ATI.
> 
> See commit:
> f2aac4c73c99 ("ata: libata-core: Add ATA_QUIRK_NO_LPM_ON_ATI for certain
> Samsung SSDs").
> 
>  From earlier reports, these Samsung drives appear to handle LPM perfectly
> fine on Intel-based AHCI controllers.
> 
> 
> This LPM quirk is only for the old ATI AHCI controllers, because it was
> assumed that, just like the ATI specific quirk that disables NCQ:
> ATA_QUIRK_NO_NCQ_ON_ATI, that the AMD AHCI controllers were unaffected,
> see e.g. 7a8526a5cd51 ("libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung
> 860 and 870 SSD."):
> 
>      After verifying the chipset from the user reports, the issue appears
>      on AMD/ATI SB7x0/SB8x0/SB9x0 SATA Controllers and does not appear on
>      recent AMD SATA adapters.
> 
> 
> I guess it is possible that while the AMD AHCI controllers have fixed the
> NCQ problem with Samsung SSDs (that was troubling ATI AHCI), perhaps the
> AMD AHCI controllers still have the LPM issues with Samsung SSDS that was
> troubling ATI AHCI controllers.
> 
> 
> It this anything anyone at AMD is aware of?
> 
>  From the users report, he is using the latest available firmware from Samsung.
> 
> Considering that Samsung SSD work fine with LPM on Intel, I'm considering
> the users suggestion, to simply rename the ATA_QUIRK_NO_LPM_ON_ATI to
> ATA_QUIRK_NO_LPM_ON_ATI_AND_AMD and modify the quirk to extend to AMD AHCI
> controllers as well.
> 
I'm not aware of anything like this. Let's see if Shyam or Basavaraj have.

I think that sounds like a pragmatic approach.  We can always back it 
out later if this ends up being root caused down to a different conclusion.