Re: SATA II NCQ and multi-port support for ICH7

[Jeff Garzik <jgarzik@pobox.com>]

dhdurgee@verizon.net wrote:
> I have recently purchased an Areca ARC-5020 external eSATA II RAID to
> connect to my system.  This unit supports ICH NCQ and multi-port for
> multiple volumes.  I have connected it to my Intel DG41TY mainboard, which
> has the Intel 82801GB I/O Controller Hub (ICH7), but I find I am only
> seeing the first volume and the unit shows NCQ is inactive.
> 
> Looking at udev for the SATA-II port I see the following:
> 
> KERNEL[1247932822.419400] add      /devices/pci0000:00/0000:00:1f.2 (pci)
> UDEV_LOG=3
> ACTION=add
> DEVPATH=/devices/pci0000:00/0000:00:1f.2
> SUBSYSTEM=pci
> DRIVER=ata_piix
> PCI_CLASS=1018F
> PCI_ID=8086:27C0
> PCI_SUBSYS_ID=8086:D612
> PCI_SLOT_NAME=0000:00:1f.2
> MODALIAS=pci:v00008086d000027C0sv00008086sd0000D612bc01sc01i8f SEQNUM=1221
> 
> syslog shows the following:
> 
> ata_piix 0000:00:1f.2: PCI INT B -> GSI 19 (level, low) -> IRQ 19 ata_piix
> 0000:00:1f.2: MAP [ P0 P2 P1 P3 ]
> ata_piix 0000:00:1f.2: setting latency timer to 64
> scsi2 : ata_piix
> scsi3 : ata_piix
> ata3: SATA max UDMA/133 cmd 0xf0e0 ctl 0xf0d0 bmdma 0xf0a0 irq 19 ata4:
> SATA max UDMA/133 cmd 0xf0c0 ctl 0xf0b0 bmdma 0xf0a8 irq 19 ata3.00:
> ATA-6: Areca   ARC-5020-VOL#00, 0100 AX, max UDMA/133 ata3.00: 1052732928
> sectors, multi 16: LBA48 NCQ (depth 0/32) ata3.00: configured for UDMA/133
> scsi 2:0:0:0: Direct-Access     ATA      Areca   ARC-5020 0100 PQ: 0 ANSI:
> 5 sd 2:0:0:0: [sda] 1052732928 512-byte hardware sectors: (538 GB/501 GiB)
> sd 2:0:0:0: [sda] Write Protect is off
> sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
> sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
> support DPO or FUA
> 
> So NCQ is detected on the RAID unit but is not enabled and only one of the
> two volumes is being seen.  Am I missing something that needs to be
> enabled for the driver to support the advanced features?  Is my
> configuration loading the proper driver?  If not, how can I load it?

ata_piix is loaded for legacy IDE emulation, and is limited by IDE 
interface in number of supported ports.  NCQ is not supported by this 
interface.

ahci driver supports "native mode", with full NCQ and all ports.

ICH7 chip usually supports both legacy IDE and native AHCI modes.

	Jeff