Re: [2.6.29-rc2] Inconsistent lock state on resume in hres_timers_resume

Rafael J. Wysocki
2009-01-19T09:51:47Z

On Monday 19 January 2009, Andrey Borzenkov wrote:
> On 19 января 2009 03:17:49 Rafael J. Wysocki wrote:
> > On Sunday 18 January 2009, Andrey Borzenkov wrote:
> > > On 18 января 2009 23:21:24 Rafael J. Wysocki wrote:
> > > > > > As far as I can tell, timekeeping_resume is called via class
> > > > > > ->resume method; and according to comments in sysdev_resume()
> > > > > > and device_power_up(), they are called with interrupts
> > > > > > disabled.
> > > > > >
> > > > > > Looking at suspend_enter, irqs *are* disabled at this point.
> > > > > >
> > > > > > So it actually looks like something (may be some driver)
> > > > > > unconditionally enabled irqs in resume path.
> > > > > >
> > > > > > I believe the patch should be hold back until this is
> > > > > > clarified.
> > > > >
> > > > > That's a nice theory!
> > > >
> > > > That would be a bad bug.
> > >
>
> With sligtly modified patch:
>
> [ 133.000279] PM: Syncing filesystems ... done.
> [ 133.062027] orinoco_cs 0.0: firmware: requesting agere_sta_fw.bin
> [ 133.102942] Freezing user space processes ... (elapsed 0.02 seconds)
> done.
> [ 133.123635] Freezing remaining freezable tasks ... (elapsed 0.00 seconds)
> done.
> [ 133.124813] Suspending console(s) (use no_console_suspend to debug)
> [ 133.136151] sd 0:0:0:0: [sda] Synchronizing SCSI cache
> [ 133.648916] sd 0:0:0:0: [sda] Stopping disk
> [ 134.339703] pci 0000:01:00.0: power state changed by ACPI to D3
> [ 134.354447] e100 0000:00:0a.0: PME# enabled
> [ 134.354679] e100 0000:00:0a.0: wake-up capability enabled by ACPI
> [ 134.354845] e100 0000:00:0a.0: PCI INT A disabled
> [ 134.420836] ALI 5451 0000:00:06.0: PCI INT A disabled
> [ 134.433823] ALI 5451 0000:00:06.0: power state changed by ACPI to D3
> [ 135.192366] pata_ali 0000:00:04.0: can't derive routing for PCI INT A
> [ 135.203635] ohci_hcd 0000:00:02.0: PME# enabled
> [ 135.203854] ohci_hcd 0000:00:02.0: wake-up capability enabled by ACPI
> [ 135.203886] ohci_hcd 0000:00:02.0: PCI INT A disabled
> [ 135.220184] ACPI: Preparing to enter system sleep state S3
> [ 135.233610] ------------[ cut here ]------------
> [ 135.233624] WARNING: at /home/bor/src/linux-
> git/kernel/time/timekeeping.c:357 timekeeping_suspend+0xe9/0x230()
> [ 135.233633] Hardware name: PORTEGE 4000
> [ 135.233638] [0] Interrupts enabled in timekeeping_suspend
> [ 135.233772] Pid: 4232, comm: pm-suspend Not tainted 2.6.29-rc2-1avb #7
> [ 135.233779] Call Trace:
> [ 135.233809] [<c011f8b3>] warn_slowpath+0x73/0xd0
> [ 135.233825] [<c0143419>] ? trace_hardirqs_on_caller+0x139/0x190
> [ 135.233835] [<c014347b>] ? trace_hardirqs_on+0xb/0x10
> [ 135.233844] [<c013831a>] ? up+0x2a/0x40
> [ 135.233870] [<c02346ba>] ? acpi_os_signal_semaphore+0x25/0x29
> [ 135.233902] [<c024aea0>] ? acpi_ut_release_mutex+0x54/0x58
> [ 135.233935] [<c02423f9>] ? acpi_get_data+0x51/0x60
> [ 135.233952] [<c024c5c7>] ? acpi_bus_data_handler+0x0/0x5
> [ 135.233962] [<c024be26>] ? acpi_bus_get_device+0x20/0x32
> [ 135.233973] [<c024bec6>] ? acpi_bus_power_manageable+0xe/0x25
> [ 135.234002] [<c02226a4>] ? acpi_pci_power_manageable+0x14/0x20
> [ 135.234012] [<c021c972>] ? pci_set_power_state+0x92/0x2c0
> [ 135.234049] [<c021ab5a>] ? pci_find_capability+0x5a/0x80
> [ 135.234059] [<c013ac19>] timekeeping_suspend+0xe9/0x230
> [ 135.234090] [<c0273825>] sysdev_suspend+0xb5/0x270
> [ 135.234119] [<c0278adf>] ? device_pm_lock+0xf/0x20
> [ 135.234128] [<c027944f>] device_power_down+0xef/0x110
> [ 135.234156] [<c0150612>] suspend_devices_and_enter+0xb2/0x150
> [ 135.234167] [<c0150e1f>] ? freeze_processes+0x3f/0x90
> [ 135.234176] [<c0150804>] enter_state+0xf4/0x140
> [ 135.234185] [<c01508cd>] state_store+0x7d/0xc0
> [ 135.234193] [<c0150850>] ? state_store+0x0/0xc0
> [ 135.234219] [<c0202f94>] kobj_attr_store+0x24/0x30
> [ 135.234229] [<c01dd72c>] sysfs_write_file+0x9c/0x100
> [ 135.234262] [<c019935c>] vfs_write+0x9c/0x160
> [ 135.234277] [<c0103494>] ? restore_nocheck_notrace+0x0/0xe
> [ 135.234285] [<c01dd690>] ? sysfs_write_file+0x0/0x100
> [ 135.234294] [<c01994dd>] sys_write+0x3d/0x70
> [ 135.234303] [<c0103371>] sysenter_do_call+0x12/0x31
> [ 135.234310] ---[ end trace 0160afff8645b4ac ]---
>
> I am absolutely confused. According to Documentation/power/devices.txt,
> timekeeping_suspend and timekeeping_resume are class interfaces and allowed
> to sleep. "Allowed to sleep" means to me - irqa enabled? But
> device_power_down obviously runs under irqs disabled?

That's correct, device_power_down() runs with interrupts off, so
timekeeping_resume() is not allowed to sleep.

However, I suspect the problem is somewhere else.

Can you apply the patch I sent earlier in this thread
(http://lkml.org/lkml/2009/1/18/183) and retest?

Thanks,
Rafael