15b46903dSGuenter Roeck.. SPDX-License-Identifier: GPL-2.0 25b46903dSGuenter Roeck 35b46903dSGuenter RoeckKernel driver drivetemp 45b46903dSGuenter Roeck======================= 55b46903dSGuenter Roeck 65b46903dSGuenter Roeck 75b46903dSGuenter RoeckReferences 85b46903dSGuenter Roeck---------- 95b46903dSGuenter Roeck 105b46903dSGuenter RoeckANS T13/1699-D 115b46903dSGuenter RoeckInformation technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS) 125b46903dSGuenter Roeck 135b46903dSGuenter RoeckANS Project T10/BSR INCITS 513 145b46903dSGuenter RoeckInformation technology - SCSI Primary Commands - 4 (SPC-4) 155b46903dSGuenter Roeck 165b46903dSGuenter RoeckANS Project INCITS 557 175b46903dSGuenter RoeckInformation technology - SCSI / ATA Translation - 5 (SAT-5) 185b46903dSGuenter Roeck 195b46903dSGuenter Roeck 205b46903dSGuenter RoeckDescription 215b46903dSGuenter Roeck----------- 225b46903dSGuenter Roeck 235b46903dSGuenter RoeckThis driver supports reporting the temperature of disk and solid state 245b46903dSGuenter Roeckdrives with temperature sensors. 255b46903dSGuenter Roeck 265b46903dSGuenter RoeckIf supported, it uses the ATA SCT Command Transport feature to read 275b46903dSGuenter Roeckthe current drive temperature and, if available, temperature limits 285b46903dSGuenter Roeckas well as historic minimum and maximum temperatures. If SCT Command 295b46903dSGuenter RoeckTransport is not supported, the driver uses SMART attributes to read 305b46903dSGuenter Roeckthe drive temperature. 315b46903dSGuenter Roeck 325b46903dSGuenter Roeck 33*e4035839SGuenter RoeckUsage Note 34*e4035839SGuenter Roeck---------- 35*e4035839SGuenter Roeck 36*e4035839SGuenter RoeckReading the drive temperature may reset the spin down timer on some drives. 37*e4035839SGuenter RoeckThis has been observed with WD120EFAX drives, but may be seen with other 38*e4035839SGuenter Roeckdrives as well. The same behavior is observed if the 'hdtemp' or 'smartd' 39*e4035839SGuenter Roecktools are used to access the drive. 40*e4035839SGuenter RoeckWith the WD120EFAX drive, reading the drive temperature using the drivetemp 41*e4035839SGuenter Roeckdriver is still possible _after_ it transitioned to standby mode, and 42*e4035839SGuenter Roeckreading the drive temperature in this mode will not cause the drive to 43*e4035839SGuenter Roeckchange its mode (meaning the drive will not spin up). It is unknown if other 44*e4035839SGuenter Roeckdrives experience similar behavior. 45*e4035839SGuenter Roeck 46*e4035839SGuenter RoeckA known workaround for WD120EFAX drives is to read the drive temperature at 47*e4035839SGuenter Roeckintervals larger than twice the spin-down time. Otherwise affected drives 48*e4035839SGuenter Roeckwill never spin down. 49*e4035839SGuenter Roeck 50*e4035839SGuenter Roeck 515b46903dSGuenter RoeckSysfs entries 525b46903dSGuenter Roeck------------- 535b46903dSGuenter Roeck 545b46903dSGuenter RoeckOnly the temp1_input attribute is always available. Other attributes are 555b46903dSGuenter Roeckavailable only if reported by the drive. All temperatures are reported in 565b46903dSGuenter Roeckmilli-degrees Celsius. 575b46903dSGuenter Roeck 585b46903dSGuenter Roeck======================= ===================================================== 595b46903dSGuenter Roecktemp1_input Current drive temperature 605b46903dSGuenter Roecktemp1_lcrit Minimum temperature limit. Operating the device below 615b46903dSGuenter Roeck this temperature may cause physical damage to the 625b46903dSGuenter Roeck device. 635b46903dSGuenter Roecktemp1_min Minimum recommended continuous operating limit 645b46903dSGuenter Roecktemp1_max Maximum recommended continuous operating temperature 655b46903dSGuenter Roecktemp1_crit Maximum temperature limit. Operating the device above 665b46903dSGuenter Roeck this temperature may cause physical damage to the 675b46903dSGuenter Roeck device. 685b46903dSGuenter Roecktemp1_lowest Minimum temperature seen this power cycle 695b46903dSGuenter Roecktemp1_highest Maximum temperature seen this power cycle 705b46903dSGuenter Roeck======================= ===================================================== 71