Re: [BUG] ata: ahci: regression in f7870e8d345c disables DevSleep for ACS-5 drives on PSC=0/SSC=0/SDS=1 controllers

[Niklas Cassel <cassel@kernel.org>]

Hello Patrick,

On Mon, Apr 06, 2026 at 05:51:39PM +0200, Patrick Zima wrote:
> You are right, (and yes to Damien, I had AI consolidate my findings)
> I need to investigate further - my drives definitely hibernate with kernel -18 and remain sleeping only with -20 
> 
> but ...
> - the commit doesn't really seem to affect my controller ASM1164 (AHCI_HFLAG_USE_LPM_POLICY) as it seems to fire for Intel mobile chipsets only                                             
> - still, the libata.ko and libahci.ko are identical between my two kernel versions — no LPM code changed for this controller
> - I initially followed the path: link_power_management_policy reverting to keep_firmware_settings after afirst reboot after -20 kernel installed
> 
> To sum it up, my initial result, leading me to file the bug was wrong
> 
> Sorry

No need to say sorry, it sounds like you have a regression on real hardware
(which was not clear from your previous mail).

Please provide as much information as possible, so we can help you find the
root cause.

Can you please test with the latest upstream kernel? 7.0-rc7 to see if the
problem still exists there? (Your distro usually provides the config it is
using in /boot/config-*, and it makes sense to use the same config as your
distro.)


Kind regards,
Niklas