xref: /linux/Documentation/scsi/link_power_management_policy.rst (revision 6f7e6393d1ce636bb7ec77a7fe7b77458fddf701)
1.. SPDX-License-Identifier: GPL-2.0
2
3==========================
4Link Power Managent Policy
5==========================
6
7This parameter allows the user to set the link (interface) power management.
8There are 6 possible options:
9
10======================  =====================================================
11Value			Effect
12======================  =====================================================
13min_power		Enable slumber mode(no partial mode) for the link to
14			use the least possible power when possible.  This may
15			sacrifice some performance due to increased latency
16			when coming out of lower power states.
17
18max_performance		Generally, this means no power management.  Tell
19			the controller to have performance be a priority
20			over power management.
21
22medium_power		Tell the controller to enter a lower power state
23			when possible, but do not enter the lowest power
24			state, thus improving latency over min_power setting.
25
26keep_firmware_settings	Do not change the current firmware settings for
27			Power management. This is the default setting.
28
29med_power_with_dipm	Same as medium_power, but additionally with
30			Device-initiated power management(DIPM) enabled,
31			as Intel Rapid Storage Technology(IRST) does.
32
33min_power_with_partial	Same as min_power, but additionally with partial
34			power state enabled, which may improve performance
35			over min_power setting.
36======================  =====================================================
37