forked from luck/tmp_suning_uos_patched
e403583909
On some drives, reading the drive temperature resets the drive's spin-down timer. If the drive temperature is read too often, affected drives will never spin down. Add this information as usage note to the driver documentation. Reported-by: Peter Sulyok <peter@sulyok.net> Cc: Peter Sulyok <peter@sulyok.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
71 lines
2.4 KiB
ReStructuredText
71 lines
2.4 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
Kernel driver drivetemp
|
|
=======================
|
|
|
|
|
|
References
|
|
----------
|
|
|
|
ANS T13/1699-D
|
|
Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
|
|
|
|
ANS Project T10/BSR INCITS 513
|
|
Information technology - SCSI Primary Commands - 4 (SPC-4)
|
|
|
|
ANS Project INCITS 557
|
|
Information technology - SCSI / ATA Translation - 5 (SAT-5)
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
This driver supports reporting the temperature of disk and solid state
|
|
drives with temperature sensors.
|
|
|
|
If supported, it uses the ATA SCT Command Transport feature to read
|
|
the current drive temperature and, if available, temperature limits
|
|
as well as historic minimum and maximum temperatures. If SCT Command
|
|
Transport is not supported, the driver uses SMART attributes to read
|
|
the drive temperature.
|
|
|
|
|
|
Usage Note
|
|
----------
|
|
|
|
Reading the drive temperature may reset the spin down timer on some drives.
|
|
This has been observed with WD120EFAX drives, but may be seen with other
|
|
drives as well. The same behavior is observed if the 'hdtemp' or 'smartd'
|
|
tools are used to access the drive.
|
|
With the WD120EFAX drive, reading the drive temperature using the drivetemp
|
|
driver is still possible _after_ it transitioned to standby mode, and
|
|
reading the drive temperature in this mode will not cause the drive to
|
|
change its mode (meaning the drive will not spin up). It is unknown if other
|
|
drives experience similar behavior.
|
|
|
|
A known workaround for WD120EFAX drives is to read the drive temperature at
|
|
intervals larger than twice the spin-down time. Otherwise affected drives
|
|
will never spin down.
|
|
|
|
|
|
Sysfs entries
|
|
-------------
|
|
|
|
Only the temp1_input attribute is always available. Other attributes are
|
|
available only if reported by the drive. All temperatures are reported in
|
|
milli-degrees Celsius.
|
|
|
|
======================= =====================================================
|
|
temp1_input Current drive temperature
|
|
temp1_lcrit Minimum temperature limit. Operating the device below
|
|
this temperature may cause physical damage to the
|
|
device.
|
|
temp1_min Minimum recommended continuous operating limit
|
|
temp1_max Maximum recommended continuous operating temperature
|
|
temp1_crit Maximum temperature limit. Operating the device above
|
|
this temperature may cause physical damage to the
|
|
device.
|
|
temp1_lowest Minimum temperature seen this power cycle
|
|
temp1_highest Maximum temperature seen this power cycle
|
|
======================= =====================================================
|