1*4882a593Smuzhiyun.. SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun 3*4882a593SmuzhiyunKernel driver drivetemp 4*4882a593Smuzhiyun======================= 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun 7*4882a593SmuzhiyunReferences 8*4882a593Smuzhiyun---------- 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunANS T13/1699-D 11*4882a593SmuzhiyunInformation technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS) 12*4882a593Smuzhiyun 13*4882a593SmuzhiyunANS Project T10/BSR INCITS 513 14*4882a593SmuzhiyunInformation technology - SCSI Primary Commands - 4 (SPC-4) 15*4882a593Smuzhiyun 16*4882a593SmuzhiyunANS Project INCITS 557 17*4882a593SmuzhiyunInformation technology - SCSI / ATA Translation - 5 (SAT-5) 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun 20*4882a593SmuzhiyunDescription 21*4882a593Smuzhiyun----------- 22*4882a593Smuzhiyun 23*4882a593SmuzhiyunThis driver supports reporting the temperature of disk and solid state 24*4882a593Smuzhiyundrives with temperature sensors. 25*4882a593Smuzhiyun 26*4882a593SmuzhiyunIf supported, it uses the ATA SCT Command Transport feature to read 27*4882a593Smuzhiyunthe current drive temperature and, if available, temperature limits 28*4882a593Smuzhiyunas well as historic minimum and maximum temperatures. If SCT Command 29*4882a593SmuzhiyunTransport is not supported, the driver uses SMART attributes to read 30*4882a593Smuzhiyunthe drive temperature. 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun 33*4882a593SmuzhiyunUsage Note 34*4882a593Smuzhiyun---------- 35*4882a593Smuzhiyun 36*4882a593SmuzhiyunReading the drive temperature may reset the spin down timer on some drives. 37*4882a593SmuzhiyunThis has been observed with WD120EFAX drives, but may be seen with other 38*4882a593Smuzhiyundrives as well. The same behavior is observed if the 'hdtemp' or 'smartd' 39*4882a593Smuzhiyuntools are used to access the drive. 40*4882a593SmuzhiyunWith the WD120EFAX drive, reading the drive temperature using the drivetemp 41*4882a593Smuzhiyundriver is still possible _after_ it transitioned to standby mode, and 42*4882a593Smuzhiyunreading the drive temperature in this mode will not cause the drive to 43*4882a593Smuzhiyunchange its mode (meaning the drive will not spin up). It is unknown if other 44*4882a593Smuzhiyundrives experience similar behavior. 45*4882a593Smuzhiyun 46*4882a593SmuzhiyunA known workaround for WD120EFAX drives is to read the drive temperature at 47*4882a593Smuzhiyunintervals larger than twice the spin-down time. Otherwise affected drives 48*4882a593Smuzhiyunwill never spin down. 49*4882a593Smuzhiyun 50*4882a593Smuzhiyun 51*4882a593SmuzhiyunSysfs entries 52*4882a593Smuzhiyun------------- 53*4882a593Smuzhiyun 54*4882a593SmuzhiyunOnly the temp1_input attribute is always available. Other attributes are 55*4882a593Smuzhiyunavailable only if reported by the drive. All temperatures are reported in 56*4882a593Smuzhiyunmilli-degrees Celsius. 57*4882a593Smuzhiyun 58*4882a593Smuzhiyun======================= ===================================================== 59*4882a593Smuzhiyuntemp1_input Current drive temperature 60*4882a593Smuzhiyuntemp1_lcrit Minimum temperature limit. Operating the device below 61*4882a593Smuzhiyun this temperature may cause physical damage to the 62*4882a593Smuzhiyun device. 63*4882a593Smuzhiyuntemp1_min Minimum recommended continuous operating limit 64*4882a593Smuzhiyuntemp1_max Maximum recommended continuous operating temperature 65*4882a593Smuzhiyuntemp1_crit Maximum temperature limit. Operating the device above 66*4882a593Smuzhiyun this temperature may cause physical damage to the 67*4882a593Smuzhiyun device. 68*4882a593Smuzhiyuntemp1_lowest Minimum temperature seen this power cycle 69*4882a593Smuzhiyuntemp1_highest Maximum temperature seen this power cycle 70*4882a593Smuzhiyun======================= ===================================================== 71