xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

scsi: ufs: Add support for Auto-Hibernate Idle Timer

Browse Source 
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>
This commit is contained in:
Adrian Hunter
2018-03-20 15:07:38 +02:00
committed by Martin K. Petersen
parent 114c1aa210
commit ad44837882
5 changed files with 126 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
Documentation/ABI/testing/sysfs-driver-ufs
View File

@@ -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>