[Ubuntu Wiki] Update of "DebuggingKernelSuspendHibernateResume" by vanessaezekowitz

[Ubuntu Wiki]

Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Ubuntu Wiki" for change notification.

The "DebuggingKernelSuspendHibernateResume" page has been changed by vanessaezekowitz:
http://wiki.ubuntu.com/DebuggingKernelSuspendHibernateResume?action=diff&rev1=22&rev2=23

  
  This page is aimed to help you do initial triage and debug of suspend/resume or hibernate/resume bugs as reported by apport. This page presents some background information as to how the reporting works, and then will take you through a series of debug steps recommending information and data which will need to be collected.
  
- The primary source of reports of suspend and hibernate failures arrive via apport. Apport checks at boot time whether there was a suspend or hibernate in progress, if we are booting normally then that was never resumed and therefore has failed. This means that the failure may have occured some time before the report is generated. Bear this in mind when answering the questions below.
+ The primary source of reports of suspend and hibernate failures arrive via apport. Apport checks at boot time whether there was a suspend or hibernate in progress, if we are booting normally then that was never resumed and therefore has failed. This means that the failure may have occurred some time before the report is generated. Bear this in mind when answering the questions below.
  
  == Bug Validation ==
  
@@ -21, +21 @@

  
  === Is this a repetition of a previous failure? ===
  
- If this is another occurance of a previous reported failure it is best to mark the new bug a duplicate of the first using the Mark Duplicate link on the bug report.
+ If this is another occurrence of a previous reported failure it is best to mark the new bug a duplicate of the first using the Mark Duplicate link on the bug report.
  
  == Information Gathering ==
  
@@ -88, +88 @@

  
  [[https://help.ubuntu.com/community/EncryptedHome|https://help.ubuntu.com/community/EncryptedHome|target="https://help.ubuntu.com/community/EncryptedHome"]]
  
- Users installing from Ubuntu 9.10 and selecting the Encrypted Home option will automatically have encrypted swap space. Other users may have also ran sudo ecryptfs-setup-swap. It is important to note that Hibernation will work with an encrypted swap but resume will fail. There are ways around this, but theyinvolve choosing a password to use for your encrypted swap and entering that password every time you boot your system, and sharing that password with anyone else that might want to resume the system. This is a known, wishlist [[https://bugs.launchpad.net/ecryptfs/+bug/432785|issue|target="https://bugs.launchpad.net/ecryptfs/+bug/432785"]] that we hope to solve. If you happen to report or triage this type of issue, please tag the bug '''encrypted-swap'''. For triagers, posting the following comment to a bug may help:
+ Users installing from Ubuntu 9.10 and selecting the Encrypted Home option will automatically have encrypted swap space. Other users may have also ran sudo ecryptfs-setup-swap. It is important to note that Hibernation will work with an encrypted swap but resume will fail. There are ways around this, but they involve choosing a password to use for your encrypted swap and entering that password every time you boot your system, and sharing that password with anyone else that might want to resume the system. This is a known, wishlist [[https://bugs.launchpad.net/ecryptfs/+bug/432785|issue|target="https://bugs.launchpad.net/ecryptfs/+bug/432785"]] that we hope to solve. If you happen to report or triage this type of issue, please tag the bug '''encrypted-swap'''. For triagers, posting the following comment to a bug may help:
  ||<tablestyle="background-color: #eee">Thank you for taking the time to report this bug and helping to make Ubuntu better. It is currently a known issue that Hibernation will fail to resume due to an encrypted swap. Please refer to https://help.ubuntu.com/community/EncryptedHome for more information. We will tag this bug "encrypted-swap" so that we can track this issue going forward and possibly request additional testing. Thanks in advance for your patience and cooperation. ||
  
  == Hibernating from text mode ==
@@ -154, +154 @@

  
  Please report whether you got any additional messages. Digital photos of the screen are a sensible way to get this into the bug.
  
+ = Dead, Blank, or Black Screen on Resume =
+ 
+ In some cases, a machine can suspend or hibernate just fine, and resume from those states without issue, with the exception of waking up to a blacked-out screen.  In other words, the computer is running just fine, but the display appears dead.  If nothing else in this article solves that issue, or the text above just doesn't apply to your particular setup, there's one more thing to try - disable Kernel Mode Setting.
+ 
+ Edit your grub configuration:
+ 
+ {{{
+      sudo nano /etc/default/grub
+ }}}
+ 
+ Find the line reading:
+ 
+ {{{
+      GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
+ }}}
+ 
+ Add {{{nomodeset}}} to the end, inside the quotes:
+ 
+ {{{
+      GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"
+ }}}
+ 
+ Exit from nano and save the file.  Make grub aware of the new changes:
+ 
+ {{{
+      update-grub2
+ }}}
+ 
+ When that exits, reboot the computer normally, then test suspend and/or hibernate.  This change will persist across reboots unless you explicitly revert it.  In some cases, this will also fix another issue where the screen doesn't dim after a period of inactivity like it should, assuming it is otherwise configured to do so in your desktop environment
+ 
  = Notes =
  
  == Battery drained whilst suspended stock reply ==