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Diffstat (limited to 'Documentation/ABI/testing/sysfs-ata')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-ata | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-ata b/Documentation/ABI/testing/sysfs-ata new file mode 100644 index 00000000..0a932155 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-ata @@ -0,0 +1,99 @@ +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. |