Re: [PATCH 0/3] ata: fix deferred QC handling for port multipliers

[Heiko Stuebner <heiko@sntech.de>]

Am Mittwoch, 6. Mai 2026, 02:13:41 Mitteleuropäische Sommerzeit schrieb Tommy Kelly:
> On 5/2/26 17:59, Tommy Kelly wrote:
> > 
> > I will also apply the FBS devicetree change (5918bf2) and test with that too.
> > 
> 
> Special thank you to Heiko for the FBS support!
> His patch setting PxCMD.FBSCP works: https://lore.kernel.org/all/20260201191804.41421-2-heiko@sntech.de/

well that is a pleasant surprise :-D .

I just needed the port node to hook y phy-supply into, and therefore
checked what capabilities were supported/which properties needed to go
in there ... but really glad it helps you too :-)

Heiko


> I compiled the FBS devicetree change into u-boot (which passes the fdt to linux),
> and running on unpatched linux 6.19.12,
> FBS works, and no regressions are present.
> Logs:
> 
> > Linux version 6.19.12-200.fc43.aarch64
> > ahci-dwc fc800000.sata: supply ahci not found, using dummy regulator
> > ahci-dwc fc800000.sata: supply phy not found, using dummy regulator
> > platform fc800000.sata:sata-port@0: supply target not found, using dummy regulator
> > ahci-dwc fc800000.sata: supply ahci not found, using dummy regulator
> > ahci-dwc fc800000.sata: supply phy not found, using dummy regulator
> > platform fc800000.sata:sata-port@0: supply target not found, using dummy regulator
> > ahci-dwc fc800000.sata: supply ahci not found, using dummy regulator
> > ahci-dwc fc800000.sata: supply phy not found, using dummy regulator
> > platform fc800000.sata:sata-port@0: supply target not found, using dummy regulator
> > ahci-dwc fc800000.sata: PMPn is limited up to 5 ports
> > ahci-dwc fc800000.sata: forcing port_map 0x0 -> 0x1
> > ahci-dwc fc800000.sata: masking port_map 0x1 -> 0x1
> > ahci-dwc fc800000.sata: AHCI vers 0001.0300, 32 command slots, 6 Gbps, platform mode
> > ahci-dwc fc800000.sata: 1/1 ports implemented (port mask 0x1)
> > ahci-dwc fc800000.sata: flags: ncq sntf pm led clo only pmp fbs pio slum part ccc apst 
> > scsi host0: ahci-dwc
> > ata1: SATA max UDMA/133 mmio [mem 0xfc800000-0xfc800fff] port 0x100 irq 59 lpm-pol 0
> > ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
> > ata1.15: Port Multiplier 1.2, 0x197b:0x5755 r0, 5 ports, feat 0x5/0xf
> > ahci-dwc fc800000.sata: FBS is enabled
> > ata1.00: hard resetting link
> > ahci-dwc fc800000.sata: FBS is disabled
> > ahci-dwc fc800000.sata: FBS is enabled
> > ata1.00: SATA link up 3.0 Gbps (SStatus 123 SControl 330)
> > ata1.01: hard resetting link
> > ahci-dwc fc800000.sata: FBS is disabled
> > ahci-dwc fc800000.sata: FBS is enabled
> > ata1.01: SATA link up 6.0 Gbps (SStatus 133 SControl 330)
> > ata1.02: hard resetting link
> > ahci-dwc fc800000.sata: FBS is disabled
> > ahci-dwc fc800000.sata: FBS is enabled
> > ata1.02: SATA link up 3.0 Gbps (SStatus 123 SControl 330)
> > ata1.03: hard resetting link
> > ahci-dwc fc800000.sata: FBS is disabled
> > ahci-dwc fc800000.sata: FBS is enabled
> > ata1.03: SATA link up 6.0 Gbps (SStatus 133 SControl 330)
> > ata1.04: hard resetting link
> > ahci-dwc fc800000.sata: FBS is disabled
> > ahci-dwc fc800000.sata: FBS is enabled
> > ata1.04: SATA link up 6.0 Gbps (SStatus 133 SControl 330)
> 
> 
> Again, that is before this patch series, I see no queue_depth regression with FBS.
> As opposed to CBS which had a regression in the 6.19.x series.
> 
> I can test with this patch series + FBS if you'd like.
> 
> - Tommy
> 
>