1What: /sys/class/ata_... 2Date: August 2008 3Contact: Gwendal Grignou<gwendal@google.com> 4Description: 5 6Provide a place in sysfs for storing the ATA topology of the system. This allows 7retrieving various information about ATA objects. 8 9Files under /sys/class/ata_port 10------------------------------- 11 12 For each port, a directory ataX is created where X is the ata_port_id of 13 the port. The device parent is the ata host device. 14 15idle_irq (read) 16 17 Number of IRQ received by the port while idle [some ata HBA only]. 18 19nr_pmp_links (read) 20 21 If a SATA Port Multiplier (PM) is connected, number of link behind it. 22 23Files under /sys/class/ata_link 24------------------------------- 25 26 Behind each port, there is a ata_link. If there is a SATA PM in the 27 topology, 15 ata_link objects are created. 28 29 If a link is behind a port, the directory name is linkX, where X is 30 ata_port_id of the port. 31 If a link is behind a PM, its name is linkX.Y where X is ata_port_id 32 of the parent port and Y the PM port. 33 34hw_sata_spd_limit 35 36 Maximum speed supported by the connected SATA device. 37 38sata_spd_limit 39 40 Maximum speed imposed by libata. 41 42sata_spd 43 44 Current speed of the link [1.5, 3Gps,...]. 45 46Files under /sys/class/ata_device 47--------------------------------- 48 49 Behind each link, up to two ata device are created. 50 The name of the directory is devX[.Y].Z where: 51 - X is ata_port_id of the port where the device is connected, 52 - Y the port of the PM if any, and 53 - Z the device id: for PATA, there is usually 2 devices [0,1], 54 only 1 for SATA. 55 56class 57 Device class. Can be "ata" for disk, "atapi" for packet device, 58 "pmp" for PM, or "none" if no device was found behind the link. 59 60dma_mode 61 62 Transfer modes supported by the device when in DMA mode. 63 Mostly used by PATA device. 64 65pio_mode 66 67 Transfer modes supported by the device when in PIO mode. 68 Mostly used by PATA device. 69 70xfer_mode 71 72 Current transfer mode. 73 74id 75 76 Cached result of IDENTIFY command, as described in ATA8 7.16 and 7.17. 77 Only valid if the device is not a PM. 78 79gscr 80 81 Cached result of the dump of PM GSCR register. 82 Valid registers are: 83 0: SATA_PMP_GSCR_PROD_ID, 84 1: SATA_PMP_GSCR_REV, 85 2: SATA_PMP_GSCR_PORT_INFO, 86 32: SATA_PMP_GSCR_ERROR, 87 33: SATA_PMP_GSCR_ERROR_EN, 88 64: SATA_PMP_GSCR_FEAT, 89 96: SATA_PMP_GSCR_FEAT_EN, 90 130: SATA_PMP_GSCR_SII_GPIO 91 Only valid if the device is a PM. 92 93spdn_cnt 94 95 Number of time libata decided to lower the speed of link due to errors. 96 97ering 98 99 Formatted output of the error ring of the device. 100