Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / ABI / testing / sysfs-ata

diff --git a/kernel/Documentation/ABI/testing/sysfs-ata b/kernel/Documentation/ABI/testing/sysfs-ata
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+What:          /sys/class/ata_...
+Date:          August 2008
+Contact:       Gwendal Grignou<gwendal@google.com>
+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.
+
+idle_irq (read)
+
+       Number of IRQ received by the port while idle [some ata HBA only].
+
+nr_pmp_links (read)
+
+       If a SATA Port Multiplier (PM) is connected, number of link behind it.
+
+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.
+
+hw_sata_spd_limit
+
+       Maximum speed supported by the connected SATA device.
+
+sata_spd_limit
+
+       Maximum speed imposed by libata.
+
+sata_spd
+
+       Current speed of the link [1.5, 3Gps,...].
+
+Files under /sys/class/ata_device
+---------------------------------
+
+       Behind each link, up to two ata device 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
+       - Z the device id: for PATA, there is usually 2 devices [0,1],
+       only 1 for SATA.
+
+class
+       Device class. Can be "ata" for disk, "atapi" for packet device,
+       "pmp" for PM, or "none" if no device was found behind the link.
+
+dma_mode
+
+       Transfer modes supported by the device when in DMA mode.
+       Mostly used by PATA device.
+
+pio_mode
+
+       Transfer modes supported by the device when in PIO mode.
+       Mostly used by PATA device.
+
+xfer_mode
+
+       Current transfer mode.
+
+id
+
+       Cached result of IDENTIFY command, as described in ATA8 7.16 and 7.17.
+       Only valid if the device is not a PM.
+
+gscr
+
+       Cached result of the dump of PM GSCR register.
+       Valid registers are:
+       0:      SATA_PMP_GSCR_PROD_ID,
+       1:      SATA_PMP_GSCR_REV,
+       2:      SATA_PMP_GSCR_PORT_INFO,
+       32:     SATA_PMP_GSCR_ERROR,
+       33:     SATA_PMP_GSCR_ERROR_EN,
+       64:     SATA_PMP_GSCR_FEAT,
+       96:     SATA_PMP_GSCR_FEAT_EN,
+       130:    SATA_PMP_GSCR_SII_GPIO
+       Only valid if the device is a PM.
+
+spdn_cnt
+
+       Number of time libata decided to lower the speed of link due to errors.
+
+ering
+
+       Formatted output of the error ring of the device.