Documentation/ABI/testing/sysfs-ata

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-ata

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-ata
Extension
[no extension]
Size
4413 bytes
Lines
141
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

What:		/sys/class/ata_*
Description:
		Provide a place in sysfs for storing the ATA topology of the
		system. This allows retrieving various information about ATA
		objects.

Files under /sys/class/ata_port
-------------------------------

For each port, a directory ataX is created where X is the ata_port_id of the
port. The device parent is the ata host device.


What:		/sys/class/ata_port/ataX/nr_pmp_links
What:		/sys/class/ata_port/ataX/idle_irq
Date:		May, 2010
KernelVersion:	v2.6.37
Contact:	Gwendal Grignou <gwendal@chromium.org>
Description:
		nr_pmp_links:	(RO) If a SATA Port Multiplier (PM) is
				connected, the number of links behind it.

		idle_irq:	(RO) Number of IRQ received by the port while
				idle [some ata HBA only].


What:		/sys/class/ata_port/ataX/port_no
Date:		May, 2013
KernelVersion:	v3.11
Contact:	Gwendal Grignou <gwendal@chromium.org>
Description:
		(RO) Host local port number. While registering host controller,
		port numbers are tracked based upon number of ports available on
		the controller. This attribute is needed by udev for composing
		persistent links in /dev/disk/by-path.

Files under /sys/class/ata_link
-------------------------------

Behind each port, there is a ata_link. If there is a SATA PM in the topology, 15
ata_link objects are created.

If a link is behind a port, the directory name is linkX, where X is ata_port_id
of the port. If a link is behind a PM, its name is linkX.Y where X is
ata_port_id of the parent port and Y the PM port.


What:		/sys/class/ata_link/linkX[.Y]/hw_sata_spd_limit
What:		/sys/class/ata_link/linkX[.Y]/sata_spd_limit
What:		/sys/class/ata_link/linkX[.Y]/sata_spd
Date:		May, 2010
KernelVersion:	v2.6.37
Contact:	Gwendal Grignou <gwendal@chromium.org>
Description:
		hw_sata_spd_limit:	(RO) Maximum speed supported by the
					connected SATA device.

		sata_spd_limit:		(RO) Maximum speed imposed by libata.

		sata_spd:		(RO) Current speed of the link
					eg. 1.5, 3 Gbps etc.


Files under /sys/class/ata_device
---------------------------------

Behind each link, up to two ata devices are created.
The name of the directory is devX[.Y].Z where:
- X is ata_port_id of the port where the device is connected,
- Y the port of the PM if any, and

Annotation

Implementation Notes