1 .. SPDX-License-Identifier: GPL-2.0 2 3 Kernel driver drivetemp 4 ======================= 5 6 7 References 8 ---------- 9 10 ANS T13/1699-D 11 Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS) 12 13 ANS Project T10/BSR INCITS 513 14 Information technology - SCSI Primary Commands - 4 (SPC-4) 15 16 ANS Project INCITS 557 17 Information technology - SCSI / ATA Translation - 5 (SAT-5) 18 19 20 Description 21 ----------- 22 23 This driver supports reporting the temperature of disk and solid state 24 drives with temperature sensors. 25 26 If supported, it uses the ATA SCT Command Transport feature to read 27 the current drive temperature and, if available, temperature limits 28 as well as historic minimum and maximum temperatures. If SCT Command 29 Transport is not supported, the driver uses SMART attributes to read 30 the drive temperature. 31 32 33 Usage Note 34 ---------- 35 36 Reading the drive temperature may reset the spin down timer on some drives. 37 This has been observed with WD120EFAX drives, but may be seen with other 38 drives as well. The same behavior is observed if the 'hdtemp' or 'smartd' 39 tools are used to access the drive. 40 With the WD120EFAX drive, reading the drive temperature using the drivetemp 41 driver is still possible _after_ it transitioned to standby mode, and 42 reading the drive temperature in this mode will not cause the drive to 43 change its mode (meaning the drive will not spin up). It is unknown if other 44 drives experience similar behavior. 45 46 A known workaround for WD120EFAX drives is to read the drive temperature at 47 intervals larger than twice the spin-down time. Otherwise affected drives 48 will never spin down. 49 50 51 Sysfs entries 52 ------------- 53 54 Only the temp1_input attribute is always available. Other attributes are 55 available only if reported by the drive. All temperatures are reported in 56 milli-degrees Celsius. 57 58 ======================= ===================================================== 59 temp1_input Current drive temperature 60 temp1_lcrit Minimum temperature limit. Operating the device below 61 this temperature may cause physical damage to the 62 device. 63 temp1_min Minimum recommended continuous operating limit 64 temp1_max Maximum recommended continuous operating temperature 65 temp1_crit Maximum temperature limit. Operating the device above 66 this temperature may cause physical damage to the 67 device. 68 temp1_lowest Minimum temperature seen this power cycle 69 temp1_highest Maximum temperature seen this power cycle 70 ======================= =====================================================
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