Re: [linux-pm] Invalid opcode on resume from STR on Asus P4P800-VM

From: Robert Hancock
Date: Mon Apr 26 2010 - 21:07:50 EST


On 04/26/2010 02:34 PM, Alan Stern wrote:
On Mon, 26 Apr 2010, Ondrej Zary wrote:

On Monday 26 April 2010 21:17:27 Alan Stern wrote:
On Mon, 26 Apr 2010, Ondrej Zary wrote:
Hello,
I'm trying to debug oops on resume from suspend-to-RAM on Asus P4P800-VM
mainboard. It crashes with invalid opcode (see below). The kernel is
2.6.32-trunk from Debian but the same problem is present with vanilla
kernels - both newer and older (but screen remains blank most of the
time, only keyboard LEDs blink indicating an oops).

What can cause this problem?

8.000339 invalid opcode: 0000 [#1] SMP
8.003529 last sysfs file: /sys/power/state
8.004265 Modules linked in: sco bridge stp bnep l2cacp crc16
bluetooth rfkill loop i2c_i801 snd_intel8x0 snd_ac97_codec shpchp
ac97_bus parport_pc parport
rng_core pci_hotplug snd_pcsp snd_pcm snd_timer snd soundcore psmouse
snd_page_alloc serio_raw evdev processor ext3 jbd mbcache ide_gd_mod
ata_generic libata scsi_mod
ide_pci_generic i915 drm_kms_helper uhci_hcd drm i2c_algo_bit piix
i2c_core ehci_hcd intel_agp e100 video ide_core mii floppy agpgart output
usbcore nls_base button
thermal fan thermal_sys [last unloaded: scsi_wait_scan]
[ 148.004265]
[ 148.004265] Pid: 0, comm: swapper Not tainted (2.6.32-trunk-686 #1) To
Be Filled By O.E.M. [ 148.004265] EIP: 0060:[<c1008ff3>] EFLAGS:
00010086 CPU: 0
[ 148.004265] EIP is at mwait_idle+0x4e/0x6c

I had exactly the same problem (on an HP computer with an Intel
chipset). As far as anyone could figure out, it is caused by a bug in
the BIOS. It's not entirely clear that this is the complete answer,
but nothing else turned up. See

http://bugzilla.kernel.org/show_bug.cgi?id=15385

for the complete record. The best solution I could find was to boot
with "idle=halt" on the command line. You might check to see if any
BIOS updates are available.

Thanks, it does not crash with "idle=halt" or "idle=poll". According to this:
http://siyobik.info/index.php?module=x86&id=215
the MWAIT instruction can be enabled/disabled in IA32_MISC_ENABLES MSR. Kernel
probably should enable it at boot and also on resume.
Here's some more info:
http://software.intel.com/en-us/forums/showthread.php?t=63654

That could be the answer. Clearly this should be handled by the
arch-specific boot/setup code. I don't know enough about it, but other
people do.

It looks like idle=nomwait should be the workaround with the least impact at the moment..
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