diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2018-03-20 15:07:38 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2018-03-21 21:21:25 -0400 |
| commit | ad448378825f5746c5fa37718724bc8f4e7b6945 (patch) | |
| tree | 0ebb00a59acf4e870228d90900fe8c39b5dfbc30 /Documentation/ABI | |
| parent | 114c1aa210494a02c26aa33f793e5b641df01989 (diff) | |
scsi: ufs: Add support for Auto-Hibernate Idle Timer
UFS host controllers may support an autonomous power management feature
called the Auto-Hibernate Idle Timer. The timer is set to the number of
microseconds of idle time before the UFS host controller will autonomously
put the link into Hibernate state. That will save power at the expense of
increased latency. Any access to the host controller interface registers
will automatically put the link out of Hibernate state. So once configured,
the feature is transparent to the driver.
Expose the Auto-Hibernate Idle Timer value via SysFS to allow users to
choose between power efficiency or lower latency. Set a default value of
150 ms.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-driver-ufs | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs index 83735f79e572..016724ec26d5 100644 --- a/Documentation/ABI/testing/sysfs-driver-ufs +++ b/Documentation/ABI/testing/sysfs-driver-ufs @@ -1,3 +1,17 @@ +What: /sys/bus/*/drivers/ufshcd/*/auto_hibern8 +Date: March 2018 +Contact: linux-scsi@vger.kernel.org +Description: + This file contains the auto-hibernate idle timer setting of a + UFS host controller. A value of '0' means auto-hibernate is not + enabled. Otherwise the value is the number of microseconds of + idle time before the UFS host controller will autonomously put + the link into hibernate state. That will save power at the + expense of increased latency. Note that the hardware supports + 10-bit values with a power-of-ten multiplier which allows a + maximum value of 102300000. Refer to the UFS Host Controller + Interface specification for more details. + What: /sys/bus/platform/drivers/ufshcd/*/device_descriptor/device_type Date: February 2018 Contact: Stanislav Nijnikov <stanislav.nijnikov@wdc.com> |