diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-18 11:09:43 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-18 11:09:43 -0700 |
commit | 395c4342920b5abd082e74af3808a74f221e2fdc (patch) | |
tree | 4c998ccea353af89ec679310aed16cce30371b5e /Documentation/power/basic-pm-debugging.txt | |
parent | Merge tag 'drm-fixes-for-4.8-rc3' of git://people.freedesktop.org/~airlied/linux (diff) | |
parent | Merge branch 'pm-sleep' (diff) | |
download | linux-dev-395c4342920b5abd082e74af3808a74f221e2fdc.tar.xz linux-dev-395c4342920b5abd082e74af3808a74f221e2fdc.zip |
Merge tag 'pm-4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"More hibernation-related material: one fix for a recent regression in
the core, one small cleanup of the x86-64 resume code and a
documentation update.
Specifics:
- Fix a hibernate core regression resulting from uncovering a latent
bug in its implementation of memory bitmaps by a recent commit
(James Morse).
- Use __pa() to compute a physical address in the x86-64 code
finalizing resume from hibernation (Rafael Wysocki).
- Update power management documentation related to system sleep
states to remove outdated information from it and to add a
description of a recently introduced hibernation debug feature to
it (Rafael Wysocki)"
* tag 'pm-4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / hibernate: Fix rtree_next_node() to avoid walking off list ends
x86/power/64: Use __pa() for physical address computation
PM / sleep: Update some system sleep documentation
Diffstat (limited to 'Documentation/power/basic-pm-debugging.txt')
-rw-r--r-- | Documentation/power/basic-pm-debugging.txt | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/Documentation/power/basic-pm-debugging.txt b/Documentation/power/basic-pm-debugging.txt index b96098ccfe69..708f87f78a75 100644 --- a/Documentation/power/basic-pm-debugging.txt +++ b/Documentation/power/basic-pm-debugging.txt @@ -164,7 +164,32 @@ load n/2 modules more and try again. Again, if you find the offending module(s), it(they) must be unloaded every time before hibernation, and please report the problem with it(them). -c) Advanced debugging +c) Using the "test_resume" hibernation option + +/sys/power/disk generally tells the kernel what to do after creating a +hibernation image. One of the available options is "test_resume" which +causes the just created image to be used for immediate restoration. Namely, +after doing: + +# echo test_resume > /sys/power/disk +# echo disk > /sys/power/state + +a hibernation image will be created and a resume from it will be triggered +immediately without involving the platform firmware in any way. + +That test can be used to check if failures to resume from hibernation are +related to bad interactions with the platform firmware. That is, if the above +works every time, but resume from actual hibernation does not work or is +unreliable, the platform firmware may be responsible for the failures. + +On architectures and platforms that support using different kernels to restore +hibernation images (that is, the kernel used to read the image from storage and +load it into memory is different from the one included in the image) or support +kernel address space randomization, it also can be used to check if failures +to resume may be related to the differences between the restore and image +kernels. + +d) Advanced debugging In case that hibernation does not work on your system even in the minimal configuration and compiling more drivers as modules is not practical or some |