Hello there, This issue came to surface when I used my ASM1166 card with an external SATA II JMB393 RAID PMP module. In kernel 6.8 I get: ahci 0000:02:00.0: AHCI 0001.0301 32 slots 32 ports 6 Gbps 0x3f impl SATA mode ahci 0000:02:00.0: flags: 64bit ncq sntf stag pm led only pio slum part deso sadm sds apst In kernel 6.6 I get: ahci 0000:02:00.0: AHCI 0001.0301 32 slots 32 ports 6 Gbps 0xffffff3f impl SATA mode ahci 0000:02:00.0: flags: 64bit ncq sntf stag pm led only pio slum part deso sadm sds apst PMP is attached at port #1 of the ASM116. Two SSDs are at port A and B of the PMP. In kernel 6.8 I can only see one SSD: ata7: SATA link up 3.0 Gbps (SStatus 123 SControl 300) In kernel 6.6 I can see both SSDs: ata7: SATA link up 3.0 Gbps (SStatus 123 SControl 300) ata15: SATA link up 3.0 Gbps (SStatus 123 SControl 300) ASM1166 is not declaring PMP compliance at its capabilities but it works on its own way if it is not touched. Upon touching it PMP support is effectively disabled so only the first attached device is visible. I believe the hflag is needed here. The safest option would be a configurable parameter to set it per case. My PMP can be set to RAID mode so it is possible to break RAID arrays if a PMP is used on that ASMedia host or older ones. Best regards, Ioannis