2.6.32-rc1: various BUGs on resume from hibernation

2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

I'm seeing a variety of BUGs on my EeePC 701 after hibernation.  
Sometimes they cause a hang during resume; sometimes they happen just 
after resume.  It doesn't happen all the time either -  I've just 
hibernated three times in a row with no problems.  It's most perplexing.

One resume hang showed a series of SCSI backtraces and errors.  
Unfortunately I wasn't able to capture it at the time.  They were most 
probably related to the root device, an SSD controlled by ata_piix.

Today on latest -git I captured this "bad swap file entry" problem.  I 
use a swap file for hibernation (I don't have a swap partition).

    Restarting tasks ... done.
    PM: Basic memory bitmaps freed
    swap_dup: Bad swap file entry 50055555
    swap_free: Bad swap file entry 50055555
    BUG: Bad page map in process kded4  pte:aaaaaa00aaaaaa pmd:173a1067
    addr:b2c71000 vm_flags:08100073 anon_vma:d77ff710 mapping:ddfdc74c
    index:a
    vma->vm_ops->fault: filemap_fault+0x0/0x2d2
    vma->vm_file->f_op->mmap: ext4_file_mmap+0x0/0x3f
    Pid: 2558, comm: kded4 Not tainted 2.6.32-rc2eeepc-test #505
    Call Trace:
    print_bad_pte+0x1f5/0x207
    unmap_vmas+0x389/0x5a6
    exit_mmap+0x81/0xe8
    mmput+0x23/0x81
    flush_old_exec+0x30c/0x54c
    ? kernel_read+0x2e/0x3e
    load_elf_binary+0x338/0x10ca
    ? get_user_pages+0x39/0x41
    ? get_arg_page+0x32/0x82
    ? put_arg_page+0x8/0xa
    search_binary_handler+0xb2/0x212
    ? load_elf_binary+0x0/0x10ca
    do_execve+0x198/0x250
    sys_execve+0x26/0x49
    sysenter_do_call+0x12/0x28
    Disabling lock debugging due to kernel taint
    ...
    (several similar traces here)

Previously, on a slightly older kernel (still after 32-rc1), I captured 
this BUG in fget_light():

Restarting tasks ...
BUG: unable to handle kernel NULL pointer dereference at (null)
fget_light+0x39/0x79
*pdpt = 000000001be15001 *pde = 0000000000000000

last sysfs file: 
/sys/devices/pci0000:00/0000:00:1b.0/sound/card0/controlC0/uevent
Modules linked in: cpufreq_stats freq_table af_packet fbcon tileblit 
font bitblit softcursor i915 drm_kms_helper drm i2c_algo_bit cfbcopyarea 
cfbimgblt cfbfillrect ipv6 loop joydev snd_hda_codec_realtek 
snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss ath5k 
snd_pcm mac80211 ath uvcvideo snd_timer snd cfg80211 psmouse i2c_i801 
videodev v4l1_compat eeepc_laptop serio_raw pcspkr i2c_core rfkill 
snd_page_alloc battery ac processor pci_hotplug evdev intel_agp video 
agpgart backlight output button thermal fan [last unloaded: scsi_wait_scan]

Pid: 2199, comm: klauncher Not tainted (2.6.32-rc2eeepc-test #483) 701
EFLAGS: 00010296 CPU: 0
EIP is at fget_light+0x39/0x79
EAX: ffffffff EBX: 00000003 ECX: 00000000 EDX: dbe23f7c
ESI: dbe23f7c EDI: b6092ff4 EBP: dbe23bd8 ESP: dbe23bd0
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process klauncher (pid: 2199, ti=dbe22000 task=dbc61840 task.ti=dbe22000)
Stack:
 00000020 dbe23e7c dbe23f8c c01a62bd 00000001 d759c400 dbc61840 00000000
<0> 08088728 08088750 00000000 dbe23e74 dbe23ea4 00000000 00000000 00000000
<0> dbe23c18 00c7afc0 c01a6eb1 ffffffff 00000000 dbc61840 00000000 00000000
Call Trace:
? do_sys_poll+0x1be/0x39b
? __pollwait+0x0/0xaf
? pollwake+0x0/0x59
? pollwake+0x0/0x59
? pollwake+0x0/0x59
? pollwake+0x0/0x59
? pollwake+0x0/0x59
? sched_clock_cpu+0xab/0xbf
? check_preempt_wakeup+0x1c6/0x1ee
? default_wake_function+0xb/0xd
? pollwake+0x4c/0x59
? default_wake_function+0x0/0xd
? __wake_up_common+0x2e/0x54
? unix_stream_recvmsg+0x2fc/0x3c2
? __wake_up_sync_key+0x2b/0x3c
? __wake_up_sync+0xa/0xd
? skb_release_data+0x81/0x85
? update_curr+0xa1/0x11a
? rb_erase+0x10a/0x218
? __switch_to+0xcc/0x15e
? finish_task_switch+0x26/0x63
? schedule+0x3c5/0x3e6
? get_signal_to_deliver+0xa7/0x2dc
? do_notify_resume+0x83/0x6b6
? autoremove_wake_function+0x0/0x30
? ktime_get_ts+0xc3/0xcd
? do_restart_poll+0x2e/0x43
? sys_restart_syscall+0x11/0x13
? sysenter_do_call+0x12/0x28
Code: 8b 88 a0 03 00 00 c7 02 00 00 00 00 8b 01 48 75 17 8b 49 04 31 d2 
3b 19 73 4b 8d 04 9d 00 00 00 00 03 41 04 8b 10 eb 3d 8b 49 04 <3b> 19 
73 34 8d 04 9d 00 00 00 00 03 41 04 8b 10 85 d2 74 26 8b
fget_light+0x39/0x79 SS:ESP 0068:dbe23bd0
CR2: 0000000000000000
---[ end trace f0a940e691d70c2d ]---
done.
PM: Basic memory bitmaps freed
...
(several similar traces here)

I have full dmesgs for both of these.

I'm afraid I can't work out how to get line numbers in my backtraces, 
despite having the obvious two options enabled -

    CONFIG_DEBUG_BUGVERBOSE=y
    CONFIG_DEBUG_INFO=y

I will keep the vmlinux for my current kernel around and try 
markup_oops.pl as soon as I capture something it can handle.

All suggestions gratefully recieved :-)
Alan

Re: 2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

Alan Jenkins wrote:
> I'm seeing a variety of BUGs on my EeePC 701 after hibernation.  
> Sometimes they cause a hang during resume; sometimes they happen just 
> after resume.  It doesn't happen all the time either -  I've just 
> hibernated three times in a row with no problems.  It's most perplexing.
>
> One resume hang showed a series of SCSI backtraces and errors.  
> Unfortunately I wasn't able to capture it at the time.  They were most 
> probably related to the root device, an SSD controlled by ata_piix.
>
> Today on latest -git I captured this "bad swap file entry" problem.  I 
> use a swap file for hibernation (I don't have a swap partition).

> Previously, on a slightly older kernel (still after 32-rc1), I 
> captured this BUG in fget_light():

And later suspend to ram failed, and then showed a hung task warning.

I've attached everything at 
<http://bugzilla.kernel.org/show_bug.cgi?id=14320>.

Thanks
Alan

Re: 2.6.32-rc1: various BUGs on resume from hibernation

[Rafael J. Wysocki]

On Sunday 04 October 2009, Alan Jenkins wrote:
> Alan Jenkins wrote:
> > I'm seeing a variety of BUGs on my EeePC 701 after hibernation.  
> > Sometimes they cause a hang during resume; sometimes they happen just 
> > after resume.  It doesn't happen all the time either -  I've just 
> > hibernated three times in a row with no problems.  It's most perplexing.
> >
> > One resume hang showed a series of SCSI backtraces and errors.  
> > Unfortunately I wasn't able to capture it at the time.  They were most 
> > probably related to the root device, an SSD controlled by ata_piix.
> >
> > Today on latest -git I captured this "bad swap file entry" problem.  I 
> > use a swap file for hibernation (I don't have a swap partition).
> 
> > Previously, on a slightly older kernel (still after 32-rc1), I 
> > captured this BUG in fget_light():
> 
> And later suspend to ram failed, and then showed a hung task warning.

As I already asked in the Bugzilla, can you verify that this is reproducible
without KMS?

Best,
Rafael

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Stefan Seyfried]

On Sun, 4 Oct 2009 22:47:43 +0200
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:
> On Sunday 04 October 2009, Alan Jenkins wrote:
> > Alan Jenkins wrote:
> > > I'm seeing a variety of BUGs on my EeePC 701 after hibernation.  
> > > Sometimes they cause a hang during resume; sometimes they happen
> > > just after resume.  It doesn't happen all the time either -  I've
> > > just hibernated three times in a row with no problems.  It's most
> > > perplexing.

> As I already asked in the Bugzilla, can you verify that this is
> reproducible without KMS?

This is important, there *are* hibernation issues with intel/KMS,
e.g. http://bugs.freedesktop.org/show_bug.cgi?id=23701
-- 
Stefan Seyfried

"Any ideas, John?"
"Well, surrounding them's out." 

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

Stefan Seyfried wrote:
> On Sun, 4 Oct 2009 22:47:43 +0200
> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>   
>> On Sunday 04 October 2009, Alan Jenkins wrote:
>>     
>>> Alan Jenkins wrote:
>>>       
>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation.  
>>>> Sometimes they cause a hang during resume; sometimes they happen
>>>> just after resume.  It doesn't happen all the time either -  I've
>>>> just hibernated three times in a row with no problems.  It's most
>>>> perplexing.
>>>>         
>
>   
>> As I already asked in the Bugzilla, can you verify that this is
>> reproducible without KMS?
>>     
>
> This is important, there *are* hibernation issues with intel/KMS,
> e.g. http://bugs.freedesktop.org/show_bug.cgi?id=23701
>   

Sure, it's definitely on my suspect list.  I'm now booting with
i915.modeset=1, which gets me back to slow and flickery VT switches
again :-).

Thanks
Alan

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

On 10/5/09, Alan Jenkins <alan-jenkins@tuffmail.co.uk> wrote:
> Stefan Seyfried wrote:
>> On Sun, 4 Oct 2009 22:47:43 +0200
>> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>>
>>> On Sunday 04 October 2009, Alan Jenkins wrote:
>>>
>>>> Alan Jenkins wrote:
>>>>
>>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation.
>>>>> Sometimes they cause a hang during resume; sometimes they happen
>>>>> just after resume.  It doesn't happen all the time either -  I've
>>>>> just hibernated three times in a row with no problems.  It's most
>>>>> perplexing.
>>>>>
>>
>>
>>> As I already asked in the Bugzilla, can you verify that this is
>>> reproducible without KMS?
>>>
>>
>> This is important, there *are* hibernation issues with intel/KMS,
>> e.g. http://bugs.freedesktop.org/show_bug.cgi?id=23701
>>
>
> Sure, it's definitely on my suspect list.  I'm now booting with
> i915.modeset=1

heh, I mean =0

, which gets me back to slow and flickery VT switches
> again :-).
>
> Thanks
> Alan
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-testers" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

Stefan Seyfried wrote:
> On Sun, 4 Oct 2009 22:47:43 +0200
> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>   
>> On Sunday 04 October 2009, Alan Jenkins wrote:
>>     
>>> Alan Jenkins wrote:
>>>       
>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation.  
>>>> Sometimes they cause a hang during resume; sometimes they happen
>>>> just after resume.  It doesn't happen all the time either -  I've
>>>> just hibernated three times in a row with no problems.  It's most
>>>> perplexing.
>>>>         
>
>   
>> As I already asked in the Bugzilla, can you verify that this is
>> reproducible without KMS?
>>     

No. I couldn't reproduce it without KMS. Then I re-enabled KMS, 
hibernated a couple of times, and had another resume hang (different 
again - this time in the freezer).

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

Alan Jenkins wrote:
> Stefan Seyfried wrote:
>> On Sun, 4 Oct 2009 22:47:43 +0200
>> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>>> On Sunday 04 October 2009, Alan Jenkins wrote:
>>>> Alan Jenkins wrote:
>>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation. 
>>>>> Sometimes they cause a hang during resume; sometimes they happen
>>>>> just after resume. It doesn't happen all the time either - I've
>>>>> just hibernated three times in a row with no problems. It's most
>>>>> perplexing.
>>
>>> As I already asked in the Bugzilla, can you verify that this is
>>> reproducible without KMS?
>
> No. I couldn't reproduce it without KMS. Then I re-enabled KMS, 
> hibernated a couple of times, and had another resume hang (different 
> again - this time in the freezer).
>

Perhaps this GEM backtrace is more relevant than the others, or perhaps 
not. I closed the lid during resume from hibernation; the screen stayed 
black when I re-opened it, but syslogd recorded the following. (Again, 
I've done the exact thing before and often nothing unusual happens) -

207.793317] ACPI: Waking up from system sleep state S4
208.480594] [drm] LVDS-8: set mode 800x480 1c
209.022770] HDA Intel 0000:00:1b.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
...
209.653483] usb 1-8: reset high speed USB device using ehci_hcd and address 3
210.134607] Restarting tasks ... done.
210.743796] ADDRCONF(NETDEV_UP): eth0: link is not ready
210.860322] ADDRCONF(NETDEV_UP): wlan0: link is not ready
211.352971] *pdpt = 00000000175e7001 *pde = 0000000000000000
211.353006] Modules linked in: af_packet fbcon tileblit font bitblit softcursor i915 drm_kms_helper drm i2c_algo_bit cfbcopyarea cfbimgblt cfbfillrect ipv6 loop joydev snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss ath5k snd_mixer_oss mac80211 ath snd_pcm uvcvideo cfg80211 psmouse i2c_i801 snd_timer videodev v4l1_compat eeepc_laptop snd serio_raw pcspkr i2c_core rfkill battery ac pci_hotplug snd_page_alloc evdev processor intel_agp video backlight output agpgart button thermal fan [last unloaded: scsi_wait_scan]
211.353126]
211.353137] Pid: 1933, comm: Xorg Not tainted (2.6.32-rc2eeepc-test #505) 701
211.353147] EIP: 0060:[<e02930fa>] EFLAGS: 00213246 CPU: 0
211.353187] EIP is at i915_gem_object_get_pages+0x96/0xf4 [i915]
(i915_gem_object_get_pages (drivers/gpu/drm/i915/i915_gem.c:2238)


00009064 <i915_gem_object_get_pages>:
...
(0x9064 + 0x96 = 0x90fa)
...
    90de:       85 d2                   test   %edx,%edx
    90e0:       89 53 24                mov    %edx,0x24(%ebx)
    90e3:       75 0a                   jne    90ef <i915_gem_object_get_pages+0x8b>
    90e5:       ff 4b 28                decl   0x28(%ebx)
    90e8:       be f4 ff ff ff          mov    $0xfffffff4,%esi
    90ed:       eb 5f                   jmp    914e <i915_gem_object_get_pages+0xea>
    90ef:       8b 55 e8                mov    -0x18(%ebp),%edx
    90f2:       31 ff                   xor    %edi,%edi
    90f4:       8b 42 0c                mov    0xc(%edx),%eax
    90f7:       8b 40 0c                mov    0xc(%eax),%eax
    90fa:       8b 40 0c                mov    0xc(%eax),%eax
    90fd:       8b 80 98 00 00 00       mov    0x98(%eax),%eax
    9103:       89 45 f0                mov    %eax,-0x10(%ebp)
    9106:       eb 31                   jmp    9139 <i915_gem_object_get_pages+0xd5>
    9108:       8b 55 f0                mov    -0x10(%ebp),%edx
    910b:       8b 42 30                mov    0x30(%edx),%eax
    910e:       89 fa                   mov    %edi,%edx
    9110:       8b 48 04                mov    0x4(%eax),%ecx
    9113:       8b 45 f0                mov    -0x10(%ebp),%eax
    9116:       6a 00                   push   $0x0
    9118:       e8 fc ff ff ff          call   9119 <i915_gem_object_get_pages+0xb5>
...


211.353197] EAX: 00000000 EBX: dbeafb80 ECX: 00000008 EDX: dbeb68a0
211.353206] ESI: dbeb68a0 EDI: 00000000 EBP: d74cfd8c ESP: d74cfd74
211.353216]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
211.353239]  dbeb68a0 00000001 dbeafb80 dbeafb80 dbeb68a0 dbd53c00 d74cfdb4 e029435c
211.353258] <0> dc341d28 00001000 dc341000 00296e52 fffffff0 dbe22800 dbd53c00 dbeafb80
211.353277] <0> d74cfdcc e029447f dbeb68a0 dbe22800 dbeafb80 de2baa20 d74cfe80 e0297090
211.353323]  [<e029435c>] ? i915_gem_object_bind_to_gtt+0x10a/0x210 [i915]
(drivers/gpu/drm/i915/i915_gem.c:2615)

211.353323]  [<e029447f>] ? i915_gem_object_pin+0x1d/0x117 [i915]
(drivers/gpu/drm/i915/i915_gem.c:3857)

211.353323]  [<e0297090>] ? i915_gem_execbuffer+0x4af/0x1031 [i915]
(drivers/gpu/drm/i915/i915_gem.c:3178)

211.353323]  [<c02ed818>] ? __kfree_skb+0x66/0x69
211.353323]  [<e029c95b>] ? intel_mark_busy+0x3a/0xb3 [i915]
(drivers/gpu/drm/i915/intel_display.c:2263)

211.353323]  [<e01c155c>] ? drm_ioctl+0x1e8/0x259 [drm]
(drivers/gpu/drm/drm_drv.c:476)

211.353323]  [<e0296be1>] ? i915_gem_execbuffer+0x0/0x1031 [i915]
211.353323]  [<c010aae7>] ? sched_clock+0xb/0x1c
211.353323]  [<c0142b23>] ? sched_clock_local+0x11/0x134
211.353323]  [<e01c1374>] ? drm_ioctl+0x0/0x259 [drm]
211.353323]  [<c01a47f8>] ? vfs_ioctl+0x3c/0x4f
211.353323]  [<c01a507c>] ? do_vfs_ioctl+0x474/0x4ac
211.353323]  [<c0123fad>] ? set_next_entity+0x1d/0x83
211.353323]  [<c0124097>] ? pick_next_task_fair+0x5b/0x6e
211.353323]  [<c0343fa4>] ? schedule+0x175/0x3e6
211.353323]  [<c01a50e0>] ? sys_ioctl+0x2c/0x45
211.353323]  [<c0107154>] ? sysenter_do_call+0x12/0x28
211.353960] ---[ end trace 99be0f1305a0c4a1 ]---
Oct  5 21:10:37 alan-eeepc kernel: [  219.229840] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
Oct  5 21:11:13 alan-eeepc kernel: [  255.136410] SysRq : Emergency Sync

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Rafael J. Wysocki]

On Monday 05 October 2009, Alan Jenkins wrote:
> Alan Jenkins wrote:
> > Stefan Seyfried wrote:
> >> On Sun, 4 Oct 2009 22:47:43 +0200
> >> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
> >>> On Sunday 04 October 2009, Alan Jenkins wrote:
> >>>> Alan Jenkins wrote:
> >>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation. 
> >>>>> Sometimes they cause a hang during resume; sometimes they happen
> >>>>> just after resume. It doesn't happen all the time either - I've
> >>>>> just hibernated three times in a row with no problems. It's most
> >>>>> perplexing.
> >>
> >>> As I already asked in the Bugzilla, can you verify that this is
> >>> reproducible without KMS?
> >
> > No. I couldn't reproduce it without KMS. Then I re-enabled KMS, 
> > hibernated a couple of times, and had another resume hang (different 
> > again - this time in the freezer).
> >
> 
> Perhaps this GEM backtrace is more relevant than the others, or perhaps 
> not. I closed the lid during resume from hibernation; the screen stayed 
> black when I re-opened it, but syslogd recorded the following. (Again, 
> I've done the exact thing before and often nothing unusual happens) -

OK, let's assume it's related to KMS, then.

1. Do we already have a Bugzilla entry for it?
2. Did it work with 2.6.31 (and with KMS)?
3. Are you aware of http://marc.info/?l=linux-kernel&m=125452324520623&w=4 ?

Thanks,
Rafael

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Rafael J. Wysocki]

On Tuesday 06 October 2009, Rafael J. Wysocki wrote:
> On Monday 05 October 2009, Alan Jenkins wrote:
> > Alan Jenkins wrote:
> > > Stefan Seyfried wrote:
> > >> On Sun, 4 Oct 2009 22:47:43 +0200
> > >> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
> > >>> On Sunday 04 October 2009, Alan Jenkins wrote:
> > >>>> Alan Jenkins wrote:
> > >>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation. 
> > >>>>> Sometimes they cause a hang during resume; sometimes they happen
> > >>>>> just after resume. It doesn't happen all the time either - I've
> > >>>>> just hibernated three times in a row with no problems. It's most
> > >>>>> perplexing.
> > >>
> > >>> As I already asked in the Bugzilla, can you verify that this is
> > >>> reproducible without KMS?
> > >
> > > No. I couldn't reproduce it without KMS. Then I re-enabled KMS, 
> > > hibernated a couple of times, and had another resume hang (different 
> > > again - this time in the freezer).
> > >
> > 
> > Perhaps this GEM backtrace is more relevant than the others, or perhaps 
> > not. I closed the lid during resume from hibernation; the screen stayed 
> > black when I re-opened it, but syslogd recorded the following. (Again, 
> > I've done the exact thing before and often nothing unusual happens) -
> 
> OK, let's assume it's related to KMS, then.
> 
> 1. Do we already have a Bugzilla entry for it?

Ah, yes, we do, http://bugzilla.kernel.org/show_bug.cgi?id=14320 (I tend to
forget about these things).

> 2. Did it work with 2.6.31 (and with KMS)?
> 3. Are you aware of http://marc.info/?l=linux-kernel&m=125452324520623&w=4 ?

Thanks,
Rafael

Re: [linux-pm] 2.6.32-rc1: various BUGs on resume from hibernation

[Alan Jenkins]

Rafael J. Wysocki wrote:
> On Monday 05 October 2009, Alan Jenkins wrote:
>   
>> Alan Jenkins wrote:
>>     
>>> Stefan Seyfried wrote:
>>>       
>>>> On Sun, 4 Oct 2009 22:47:43 +0200
>>>> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>>>>         
>>>>> On Sunday 04 October 2009, Alan Jenkins wrote:
>>>>>           
>>>>>> Alan Jenkins wrote:
>>>>>>             
>>>>>>> I'm seeing a variety of BUGs on my EeePC 701 after hibernation. 
>>>>>>> Sometimes they cause a hang during resume; sometimes they happen
>>>>>>> just after resume. It doesn't happen all the time either - I've
>>>>>>> just hibernated three times in a row with no problems. It's most
>>>>>>> perplexing.
>>>>>>>               
>>>>> As I already asked in the Bugzilla, can you verify that this is
>>>>> reproducible without KMS?
>>>>>           
>>> No. I couldn't reproduce it without KMS. Then I re-enabled KMS, 
>>> hibernated a couple of times, and had another resume hang (different 
>>> again - this time in the freezer).
>>>
>>>       
>> Perhaps this GEM backtrace is more relevant than the others, or perhaps 
>> not. I closed the lid during resume from hibernation; the screen stayed 
>> black when I re-opened it, but syslogd recorded the following. (Again, 
>> I've done the exact thing before and often nothing unusual happens) -
>>     
>
> OK, let's assume it's related to KMS, then.
>
> 1. Do we already have a Bugzilla entry for it?
> 2. Did it work with 2.6.31 (and with KMS)?
>   

I thought so, but my recollection is hazy.  I didn't test it for very
long if I did.  I've tried it now and 2.6.31 behaves pretty similarly. 
Sorry for ringing the regression bell.

Firstly the _hibernation_ process hung (after a couple of suspend-to-ram
cycles).

No text on the console (despite using s2disk).  It echoed keypresses and
responds to SysRq keys.  No messages from lockdep or the hung task
detector (after waiting 5 minutes).  SysRq-P said we're in the idle
loop; SysRq-T said both events/0 and hald-addon-input were runnable.

Then suspend-to-ram hung (following a hibernation cycle).  This time it
showed the contents of vt1, but didn't appear to respond to anything
short of SysRq+B.


> 3. Are you aware of http://marc.info/?l=linux-kernel&m=125452324520623&w=4 ?
>
> Thanks,
> Rafael
>   

I guess there's no connection.  That issue seems to be about generally
flickery screens.  I've seen a few rare flickers that might be related. 
But in general nothing bad happens until I try to suspend, and the
badness is in the form of random crashes or hangs.

Also that bug is confirmed to be a regression, and my issue isn't :-).

Many thanks
Alan