Bug 903141

Summary: Regression: Kernel 3.7.x breaks suspend/hibernation
Product: [Fedora] Fedora Reporter: Matthias Hensler <mails.bugzilla.redhat.com>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 18CC: gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda, schaiba
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Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2013-01-23 14:38:16 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Patch to fix watchdog/NMI to resolve the problem none

Description Matthias Hensler 2013-01-23 10:10:03 UTC 
Created attachment 685792 [details]
Patch to fix watchdog/NMI to resolve the problem

Description of problem:
Update to any 3.7.x kernel breaks suspend/hibernation in the freezing-process (reproduceable with a chance of 50%).

The problem was bisect at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1079534 and a fix was proposed at http://thread.gmane.org/gmane.linux.kernel/1397985

According to the author that fix is already in Linux 3.8 and should backported to 3.7, although it seems that it did not happen till now.


Version-Release number of selected component (if applicable):
3.7.2-201.fc18 and 3.7.3-201.fc18

How reproducible:
50%


Steps to Reproduce:
1. Boot affected kernel
2. Try to suspend to RAM or disk
3. With a 50% chance the system locks up while freezing. If not, just resume and try again.
  
Actual results:
System freezes.

Expected results:
System should suspend properly.

Additional info:
I attached the small patch which fixes the issue. I added the patch to the Fedora Kernel build 3.7.4-201.fc18 and can confirm that the problem is resolved.

Since I suspect that Fedora 18 will stick with Linux 3.7 for a while I suggest to add the patch until it is properly backported upstream.
Comment 1 Josh Boyer 2013-01-23 13:50:35 UTC 
The patch you point to was included in 3.7 as commit 8d4516904b39.  The thread was mistaken in that.  However, there was a subsequent patch:

commit 3935e89505a1c3ab3f3b0c7ef0eae54124f48905
Author: Bjørn Mork <bjorn>
Date:   Wed Dec 19 20:51:31 2012 +0100

    watchdog: Fix disable/enable regression
    
    Commit 8d4516904b39 ("watchdog: Fix CPU hotplug regression") causes an
    oops or hard lockup when doing

that fixes another issue.  That was backported to 3.7.4, which has been built in F18.  It would be good if you could test that and let us know if it solves your issue.
Comment 2 Matthias Hensler 2013-01-23 14:22:19 UTC 
Thanks, indeed it seems that I overlooked that patch.

However, I used 3.7.3-201.fc18 from koji since sunday evening and that build did not solve the issue. I just looked at the source and confirmed that this version did already include the patch above.

I went straight to 3.7.4-201.fc18 with the additional return-statement in watchdog_disable and had no issues so far.

What puzzles me is, that 3.7.2-201.fc18 also had the additional return-statement but did crash anyway.

So maybe both patches are needed, but I will try with the original 3.7.4-203.fc18 from koji first and check if that kernel still crashes on suspend.
Comment 3 Matthias Hensler 2013-01-23 14:38:16 UTC 
OK, I made some quick test with 3.7.4-203.fc18 from koji without any further patches and was not able to reproduce the issue.

So for the moment it seems that the bug was indeed already fixed. Sorry for the noise. I will make some further test within the next days and will report should the issue raise again.

Till then this bug can be closed.