xref: /openbmc/linux/Documentation/scsi/link_power_management_policy.rst (revision ead5d1f4d877e92c051e1a1ade623d0d30e71619)
1*cbbc70a8SMauro Carvalho Chehab.. SPDX-License-Identifier: GPL-2.0
2*cbbc70a8SMauro Carvalho Chehab
3*cbbc70a8SMauro Carvalho Chehab==========================
4*cbbc70a8SMauro Carvalho ChehabLink Power Managent Policy
5*cbbc70a8SMauro Carvalho Chehab==========================
6*cbbc70a8SMauro Carvalho Chehab
7*cbbc70a8SMauro Carvalho ChehabThis parameter allows the user to set the link (interface) power management.
8*cbbc70a8SMauro Carvalho ChehabThere are 3 possible options:
9*cbbc70a8SMauro Carvalho Chehab
10*cbbc70a8SMauro Carvalho Chehab=====================   =====================================================
11*cbbc70a8SMauro Carvalho ChehabValue			Effect
12*cbbc70a8SMauro Carvalho Chehab=====================   =====================================================
13*cbbc70a8SMauro Carvalho Chehabmin_power		Tell the controller to try to make the link use the
14*cbbc70a8SMauro Carvalho Chehab			least possible power when possible.  This may
15*cbbc70a8SMauro Carvalho Chehab			sacrifice some performance due to increased latency
16*cbbc70a8SMauro Carvalho Chehab			when coming out of lower power states.
17*cbbc70a8SMauro Carvalho Chehab
18*cbbc70a8SMauro Carvalho Chehabmax_performance		Generally, this means no power management.  Tell
19*cbbc70a8SMauro Carvalho Chehab			the controller to have performance be a priority
20*cbbc70a8SMauro Carvalho Chehab			over power management.
21*cbbc70a8SMauro Carvalho Chehab
22*cbbc70a8SMauro Carvalho Chehabmedium_power		Tell the controller to enter a lower power state
23*cbbc70a8SMauro Carvalho Chehab			when possible, but do not enter the lowest power
24*cbbc70a8SMauro Carvalho Chehab			state, thus improving latency over min_power setting.
25*cbbc70a8SMauro Carvalho Chehab=====================   =====================================================
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