xref: /openbmc/linux/kernel/power/Kconfig (revision 87c2ce3b)
1config PM
2	bool "Power Management support"
3	depends on !IA64_HP_SIM
4	---help---
5	  "Power Management" means that parts of your computer are shut
6	  off or put into a power conserving "sleep" mode if they are not
7	  being used.  There are two competing standards for doing this: APM
8	  and ACPI.  If you want to use either one, say Y here and then also
9	  to the requisite support below.
10
11	  Power Management is most important for battery powered laptop
12	  computers; if you have a laptop, check out the Linux Laptop home
13	  page on the WWW at <http://www.linux-on-laptops.com/> or
14	  Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/>
15	  and the Battery Powered Linux mini-HOWTO, available from
16	  <http://www.tldp.org/docs.html#howto>.
17
18	  Note that, even if you say N here, Linux on the x86 architecture
19	  will issue the hlt instruction if nothing is to be done, thereby
20	  sending the processor to sleep and saving power.
21
22config PM_LEGACY
23	bool "Legacy Power Management API"
24	depends on PM
25	default y
26	---help---
27	   Support for pm_register() and friends.
28
29	   If unsure, say Y.
30
31config PM_DEBUG
32	bool "Power Management Debug Support"
33	depends on PM
34	---help---
35	This option enables verbose debugging support in the Power Management
36	code. This is helpful when debugging and reporting various PM bugs,
37	like suspend support.
38
39config SOFTWARE_SUSPEND
40	bool "Software Suspend"
41	depends on PM && SWAP && (X86 && (!SMP || SUSPEND_SMP)) || ((FVR || PPC32) && !SMP)
42	---help---
43	  Enable the possibility of suspending the machine.
44	  It doesn't need APM.
45	  You may suspend your machine by 'swsusp' or 'shutdown -z <time>'
46	  (patch for sysvinit needed).
47
48	  It creates an image which is saved in your active swap. Upon next
49	  boot, pass the 'resume=/dev/swappartition' argument to the kernel to
50	  have it detect the saved image, restore memory state from it, and
51	  continue to run as before. If you do not want the previous state to
52	  be reloaded, then use the 'noresume' kernel argument. However, note
53	  that your partitions will be fsck'd and you must re-mkswap your swap
54	  partitions. It does not work with swap files.
55
56	  Right now you may boot without resuming and then later resume but
57	  in meantime you cannot use those swap partitions/files which were
58	  involved in suspending. Also in this case there is a risk that buffers
59	  on disk won't match with saved ones.
60
61	  For more information take a look at <file:Documentation/power/swsusp.txt>.
62
63config PM_STD_PARTITION
64	string "Default resume partition"
65	depends on SOFTWARE_SUSPEND
66	default ""
67	---help---
68	  The default resume partition is the partition that the suspend-
69	  to-disk implementation will look for a suspended disk image.
70
71	  The partition specified here will be different for almost every user.
72	  It should be a valid swap partition (at least for now) that is turned
73	  on before suspending.
74
75	  The partition specified can be overridden by specifying:
76
77		resume=/dev/<other device>
78
79	  which will set the resume partition to the device specified.
80
81	  Note there is currently not a way to specify which device to save the
82	  suspended image to. It will simply pick the first available swap
83	  device.
84
85config SWSUSP_ENCRYPT
86	bool "Encrypt suspend image"
87	depends on SOFTWARE_SUSPEND && CRYPTO=y && (CRYPTO_AES=y || CRYPTO_AES_586=y || CRYPTO_AES_X86_64=y)
88	default ""
89	---help---
90	  To prevent data gathering from swap after resume you can encrypt
91	  the suspend image with a temporary key that is deleted on
92	  resume.
93
94	  Note that the temporary key is stored unencrypted on disk while the
95	  system is suspended.
96
97config SUSPEND_SMP
98	bool
99	depends on HOTPLUG_CPU && X86 && PM
100	default y
101