Re: 3.12: kernel panic when resuming from suspend to RAM (x86_64)

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Sunday, November 24, 2013 10:39:20 AM Francis Moreau wrote:
> Hello Thomas
> 
> On 11/22/2013 11:27 PM, Thomas Gleixner wrote:
> > On Fri, 22 Nov 2013, Rafael J. Wysocki wrote:
> >> On Friday, November 22, 2013 10:36:23 PM Francis Moreau wrote:
> >>> Ok, I've finally managed to find out the bad commit:
> >>> ad07277e82dedabacc52c82746633680a3187d25: ACPI / PM: Hold acpi_scan_lock
> >>> over system PM transitions
> >>>
> >>> I verified that the parent commit doesn't have the problem.
> >>
> >> Interesting.
> >>
> >>> Rafael, you're the man now ;)
> >>
> >> I kind of don't see how that commit may result in behavior that you
> >> described earlier in the thread.
> >>
> >> You get a memory corruption that seems to have started to happen because
> >> we're holding an additional lock over suspend resume now.  Something's fishy
> >> on that machine and we need to figure out what it is.
> > 
> > The hickup happens in the timer softirq.
> > 
> > @Francis: Did you try to enable DEBUG_OBJECTS.*. If not please give it
> > 	  a try.
> 
> This looks like it was a good idea.
> 
> The kernel now outputs the following traces after resuming.
> 
> [   26.973928] WARNING: CPU: 0 PID: 4 at lib/debugobjects.c:260
> debug_print_object+0x83/0xa0()
> [   26.973932] ODEBUG: free active (active state 0) object type:
> timer_list hint: delayed_work_timer_fn+0x0/0x20
> [   26.973972] Modules linked in: x86_pkg_temp_thermal intel_powerclamp
> rtsx_pci_ms coretemp memstick kvm_intel i2c_i801 iTCO_wdt
> iTCO_vendor_support i915 i2c_algo_bit intel_agp intel_gtt drm_kms_helper
> r8169 drm kvm mii agpgart i2c_core lpc_ich ac shpchp crc32c_intel
> battery thermal wmi evdev mei_me video mei button mperf processor
> serio_raw microcode ext4 crc16 mbcache jbd2 sr_mod cdrom sd_mod
> usb_storage rtsx_pci_sdmmc mmc_core ahci libahci libata ehci_pci
> ehci_hcd xhci_hcd scsi_mod rtsx_pci usbcore usb_common
> [   26.974013] CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted
> 3.11.0-rc2-ARCH #64
> [   26.974014] Hardware name: CLEVO CO.                        W55xEU
>                        /W55xEU                          , BIOS 4.6.5
> 03/05/2013
> [   26.974019] Workqueue: kacpi_hotplug hotplug_event_work
> [   26.974020]  0000000000000009 ffff880407d0da18 ffffffff81459fe9
> ffff880407d0da60
> [   26.974023]  ffff880407d0da50 ffffffff8104dc7d ffff880407fad488
> ffffffff81836fc0
> [   26.974025]  ffffffff81701358 ffffffff81afef70 0000000000000003
> ffff880407d0dab0
> [   26.974027] Call Trace:
> [   26.974031]  [<ffffffff81459fe9>] dump_stack+0x54/0x8d
> [   26.974043]  [<ffffffff8104dc7d>] warn_slowpath_common+0x7d/0xa0
> [   26.974044]  [<ffffffff8104dcec>] warn_slowpath_fmt+0x4c/0x50
> [   26.974047]  [<ffffffff81261433>] debug_print_object+0x83/0xa0
> [   26.974050]  [<ffffffff8106b820>] ? queue_work_on+0x50/0x50
> [   26.974053]  [<ffffffff81261c2b>] __debug_check_no_obj_freed+0x1fb/0x240
> [   26.974059]  [<ffffffffa008e959>] ? rtsx_pci_remove+0x119/0x1d0
> [rtsx_pci]

So a device driven by rtsx_pcr.c is removed after resume.  Without the commit
you've bisected it is removed as well, but that happens during resume, so
rtsx_pci_resume() is likely not called in that case.

I bet that there's a bug either in rtsx_pci_remove() or in rtsx_pci_resume().
The latter definitely should check if the device is actually still present
before scheduling the delayed work, but then the Boris' patch should take care
of that anyway.

Thanks!

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.