billimek

Q: MBA fails to wake (Platform Failure) after entering Low Power Sleep state

2011 MacBook Air 13” model number A1369

 

 

The issue: every time the battery drains empty and the device automatically shuts off, it will not properly power-on after being charged.  The display backlight is active (and apple logo on the rear is illuminated) although the screen is blank.  The machine doesn’t respond to any command or action.  The machine will not respond to ping requests and does not appear to attempt to join the network according to the Airport logs.  Closing the clamshell and re-openning does not appear to make any difference.  The only action that yields any response is to hold the power button until it turns off and then turn it back on again.  This has happened 100% of the time since the MacBook Air was purchased. This behavior does not happen with the 2009 MacBook pro also running OSX Lion. 

 

pmset -g output:

Active Profiles:

Battery Power           -1*

AC Power                -1

Currently in use:

standbydelay   4200

standby        1

halfdim        1

panicrestart   15

hibernatefile  /var/vm/sleepimage

disksleep      10

sleep          10

hibernatemode  3

ttyskeepawake  1

displaysleep   5

acwake         0

lidwake        1

 

 

pmset -g log output of problem situation:

* Domain: sleep

- Message: Sleep: Success - BATT 0 - Low Power Sleep

- Time: 8/13/11 10:32:55 PM EDT

- Signature: Success

- UUID: 79B0FD75-93BF-4F54-9206-F88EFDD9539A

- Result: Success

- Sleep count : 0

 

* Domain: sleep

- Message: Sleep: Platform Failure - AC 82

- Time: 8/13/11 11:58:45 PM EDT

- Signature: Platform Failure

- UUID: 399B3402-C3A6-451B-B5AC-60CF6CD5176F

- Result: Failure

 

Observations:

  • FileVault is enabled
  • This issue does not seem to occur when the device enters the ‘hibernation’ state after sleeping for an extended-period of time

 

 

Actions taken (with no resolution yet):

  • SMC reset (multiple times)
  • PRAM reset
  • Set main HD (“Macintosh HD”) as Startup Disk
  • Complete reinstall of OSX Lion

 

Any advice?

MacBook Air, Mac OS X (10.7), mid-2011 13" 1.7GHz i5 model

Posted on Aug 14, 2011 9:00 PM

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Q: MBA fails to wake (Platform Failure) after entering Low Power Sleep state

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  • by cmeid,

    cmeid cmeid Dec 31, 2011 7:09 AM in response to billimek
    Level 1 (0 points)
    Dec 31, 2011 7:09 AM in response to billimek

    SOLVED???

     

    I can't believe it. I think I have a solution!

     

    Short version: try creating a new user.

     

    Long version: This problem has been so annoying the last few weeks that I put some more time into it. It happens to me serveral times a day, I'm a consultant so I'll be working on customer systems and switching to my own laptop regularly. I had returned standbydelay at 4200 at some point, so one possible solution was raising that.


    First, however, I wanted to see if some program like openvpn, f.lux, caffeine etc. that I have set up start at login was the culprit, thinking maybe something was preventing OSX from getting all the way fully asleep.

     

    I created a new user to test with, as that user would have no startupitems. Hibernation worked immediately. After confirming that user was truly working after cold boots etc., I tried it with my normal user. Suddenly, it's working properly with my normal user as well. I had never previously seen FileVault's password input screen other than at boot. For any others who are not aware, apparently FileVault will re-request the password after hibernation. After that, you will need to re-enter your password for the OSX screen lock assuming you have it enabled. (Previously, I had just assumed those two would be integrated, I'm kind of glad to see they're not.)

     

    My guess is that having enabled FileVault 2 a week after buying and installing the computer, some part of the user data was not properly written to instruct FileVault how to decrypt and enable reading the disk with DestroyFVKeyOnStandby set to 1.


    Creating a new user seems to have reinitialized whatever information the bootstrap process was missing and made it possible to resume from hibernation.

     

    Would be curious whether this helps any of the others in this thread.

  • by cmeid,

    cmeid cmeid Dec 31, 2011 7:37 AM in response to cmeid
    Level 1 (0 points)
    Dec 31, 2011 7:37 AM in response to cmeid

    Update: removing the user causes the problem to return, adding the user again eliminates the problem once more.

  • by fabian.zeindl,

    fabian.zeindl fabian.zeindl Jan 1, 2012 8:09 AM in response to cmeid
    Level 1 (1 points)
    Jan 1, 2012 8:09 AM in response to cmeid

    My noble hero! This solution works for me as well.

  • by vonkas,

    vonkas vonkas Jan 1, 2012 1:30 PM in response to cmeid
    Level 1 (0 points)
    Jan 1, 2012 1:30 PM in response to cmeid

    I had to create a new user some time back. I also noticed the probelm had dissapeared but I didn't connect the dots as I had done all sorts of other things trying to remedy the bug. So I can't be sure what fixed it. But there is a chance that "your fix" worked for me as well. Still, there is  a problem with the delay - possibly during which  decryption takes place - where the user is left not knowing what goes on. Would be nice to have some sort of wait symbol appear immediately when waking up the MB Air.

  • by cmeid,

    cmeid cmeid Jan 1, 2012 3:28 PM in response to vonkas
    Level 1 (0 points)
    Jan 1, 2012 3:28 PM in response to vonkas

    vonkas wrote:

     

    Would be nice to have some sort of wait symbol appear immediately when waking up the MB Air.

     

    I agree completely. I'm terrified every time I wake the air from sleep that it won't work. Luckily it seems to work every time so far /knock on wood/

  • by praseodym,

    praseodym praseodym Jan 3, 2012 11:07 AM in response to cmeid
    Level 1 (0 points)
    Jan 3, 2012 11:07 AM in response to cmeid

    Works for me too, but indeed breaks again when removing the user. Has anyone tested if it works when removing the current user?

  • by Spacemarine,

    Spacemarine Spacemarine Jan 12, 2012 3:18 PM in response to praseodym
    Level 1 (0 points)
    Jan 12, 2012 3:18 PM in response to praseodym

    I never had this problem, since I always had two users (one to decrypt the disk and one with a shorter password to unlock the screen, who was not able to unlock the disk)

     

    However, there is a strange problem which might be related:

     

    If I do sudo pmset -a hibernatemode 25 all data from Ram will be written to disk and the Ram will be erased upon standby. But I can still wake up and ONLY enter the weak user-password which is not able to decrypt the disk and still log in.

     

    How is this possible? Where is the key saved, if the Ram is cleared? Does it get written to disk in plain-text?

  • by cmeid,

    cmeid cmeid Jan 12, 2012 3:22 PM in response to Spacemarine
    Level 1 (0 points)
    Jan 12, 2012 3:22 PM in response to Spacemarine

    Interesting. Do you have standby set to 0 or 1 ?

     

    If set to 1, what is your standbydelay?

  • by fabian.zeindl,

    fabian.zeindl fabian.zeindl Jan 13, 2012 4:01 AM in response to Spacemarine
    Level 1 (1 points)
    Jan 13, 2012 4:01 AM in response to Spacemarine

    How can you disable decryption-ability for a user?

  • by Spacemarine,

    Spacemarine Spacemarine Jan 13, 2012 5:23 AM in response to fabian.zeindl
    Level 1 (0 points)
    Jan 13, 2012 5:23 AM in response to fabian.zeindl

    You can not. But all users that were created before you activated FV2, can not decrypt unless you explicitely enable them. So the only possibility to lock out a user from FV2 decryption is to decrypt the disk and reencrypt it again and not activate this user.

     

    @cmeid:

    I didn't change anything there. How do I find this out?

  • by cmeid,

    cmeid cmeid Jan 13, 2012 6:35 AM in response to Spacemarine
    Level 1 (0 points)
    Jan 13, 2012 6:35 AM in response to Spacemarine

    % pmset -g | grep standby

    standbydelay    4200

    standby    1

     

    Also, what setting do you have for DestroyFVKeyOnStandby ? Is that 0 or 1 ?

     

    The reason I ask, is that I see the following in the man page:

     

    STANDBY ARGUMENTS

         standby causes kernel power management to automatically hibernate a machine after it has slept for a specified time period. This saves power while asleep. This setting defaults to ON for supported hardware. The setting

         standby will be visible in pmset -g if the feature is supported on this machine.

     

         standby only works if hibernation is turned on to hibernatemode 3 or 25.

     

         standbydelay specifies the delay, in seconds, before writing the hibernation image to disk and powering off memory for Standby.

     

    So, clearly standby works with hibernatemode 25. I wonder whether setting standby to 0 would cause the behavior you are looking for.

     

    Message was edited by: cmeid to add man page info

  • by Spacemarine,

    Spacemarine Spacemarine Jan 13, 2012 1:10 PM in response to cmeid
    Level 1 (0 points)
    Jan 13, 2012 1:10 PM in response to cmeid

    I have

     

    standbydelay    4200

    standby    1

     

    Hibernatemode 0

    DestroyFVKeyOnStandby 1 (makes no sense with Hibernatemode 0)

     

    Maybe I explain my original experiment: I activated FV2 and ran the battery down to 1%. Then shut the lid and let it sleep. The next day I opened it and it was dead. I connected the power, waited a minute and opened the lid. It took much longer to wake up compared to when I reopen the lid immediately. This way I could be absolutely sure that the Ram was cleared (loss of power) and that it woke up from disk. But I was still able to log in with my weak user password, that can not be used for decryption.

     

    This means that in a standard configuration the FV2 key will be stored in a permanent location in this situation. If true, this would be a huge security risk. But where is the key stored? Does it get written to disk in plaintext?

  • by cmeid,

    cmeid cmeid Jan 13, 2012 3:16 PM in response to Spacemarine
    Level 1 (0 points)
    Jan 13, 2012 3:16 PM in response to Spacemarine

    So, the way I read the man page, standby still has an effect even though you have hibernatemode 25.

     

    Try setting standby to 0 and see if that helps.

     

    Also, just for clarity, when you say unlock the disk you mean the gray screen right?

     

    So, when you open the lid after hibernation, you are logging in twice, correct? (Once in the gray filevault login screen and again in the window manager lock screen?)

     

    Now, until now you were talking about hibernatemode 25. I assume you took that from pmset when you were on AC?

     

    Check again with pmset -b -g (this will give you the settings for when you're on battery) to make sure you're really on hibernatemode 25. If you want the behavior to work when you're on AC as well, then you need to set it that way. Hibernatemode 0 turns off disk hibernation, and always stands by to RAM.

  • by Spacemarine,

    Spacemarine Spacemarine Jan 13, 2012 3:32 PM in response to cmeid
    Level 1 (0 points)
    Jan 13, 2012 3:32 PM in response to cmeid

    I think there is a misunderstanding here. At the moment I am using hibernatemode 0, because I don't want my key to be written to the disk for everyone to read (I assume it's the disk where it gets written to as I have no other explanation where it could be read from on wake up)

     

    I USED to use hibernatemode 25 (or 3), but this was just to expose the security flaw. I'm not using this anymore.

     

    When I say "unlock the disk", I mean the gray screen, that comes first if you do a fresh boot.

     

    If I wake up from sleep (hibernatemode 25 DestroyFVKeyOnStandby 0), I ONLY enter one password on the regular screen-unlock, not the gray screen. The password I enter there is my weak user password that can not decrypt the disk.

     

    I would expect this behaviour only from hibernatemode 0 (as I have right now), but not from 25, because there should be no possibility to get around entering you decryption password. But since there is, I conclude that the decryption key must be stored in a permanent memory and that is a very severe securitry risk.

  • by cmeid,

    cmeid cmeid Jan 13, 2012 3:37 PM in response to Spacemarine
    Level 1 (0 points)
    Jan 13, 2012 3:37 PM in response to Spacemarine

    Ok, gotcha.

     

    If I wake up from sleep (hibernatemode 25), I ONLY enter one password on the regular screen-unlock, not the gray screen. The password I enter there is my weak user password that can not decrypt the disk.

     

    This is why I was wondering about setting standby to 0. If you are only getting the regular screen unlock, then the machine wasn't fully hibernating, it was just in standby. If it's hibernating (and power to RAM is off) you'll get the gray screen again.


    Try setting standby to 0 to see if it hibernates all the way immediately. I /think/ what's happening is that the image is being written to disk immediately, but RAM is not powered off until 4200 seconds have passed. Alternatively, you could turn standbydelay to 10 with hibernatemode 3. This I have tested and works at least on my box.

     

    The man page is contradictory - hibernatemode 25 claims that RAM will be powered off immediately, but standby claims to have an effect in both hibernate mode 3 and mode 25. Thus my curiousity whether turning standby off will have the effect you want.

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