On Thu, May 30, 2024 at 11:27:04PM +0200, Niklas Cassel wrote:
Commit 7627a0edef54 ("ata: ahci: Drop low power policy board type") dropped the board_ahci_low_power board type, and instead enables LPM if: -The AHCI controller reports that it supports LPM (Partial/Slumber), and -CONFIG_SATA_MOBILE_LPM_POLICY != 0, and -The port is not defined as external in the per port PxCMD register, and -The port is not defined as hotplug capable in the per port PxCMD register.
Partial and Slumber LPM states can either be initiated by HIPM or DIPM.
For HIPM (host initiated power management) to get enabled, both the AHCI controller and the drive have to report that they support HIPM.
For DIPM (device initiated power management) to get enabled, only the drive has to report that it supports DIPM. However, the HBA will reject device requests to enter LPM states which the HBA does not support.
The problem is that Apacer AS340 drives do not handle low power modes correctly. The problem was most likely not seen before because no one had used this drive with a AHCI controller with LPM enabled.
Add a quirk so that we do not enable LPM for this drive, since we see command timeouts if we do (even though the drive claims to support DIPM).
Fixes: 7627a0edef54 ("ata: ahci: Drop low power policy board type") Cc: stable@vger.kernel.org Reported-by: Tim Teichmann teichmanntim@outlook.de Closes: https://lore.kernel.org/linux-ide/87bk4pbve8.ffs@tglx/ Signed-off-by: Niklas Cassel cassel@kernel.org
Reviewed-by: Mika Westerberg mika.westerberg@linux.intel.com