Re: 2.6.31.4: WARNING: at arch/x86/kernel/hpet.c:390 hpet_next_event+0x70/0x80() [occurs when ACPI_PROCESSOR=y]

[john stultz <johnstul@us.ibm.com>]

Forgot to CC lkml, re-adding.

On Thu, 2009-11-12 at 18:25 -0500, Justin Piszcz wrote:
> On Thu, 12 Nov 2009, john stultz wrote:
> > On Thu, Nov 12, 2009 at 8:33 AM, Justin Piszcz <jpiszcz@lucidpixels.com> wrote:
> >> On Thu, 12 Nov 2009, Justin Piszcz wrote:
> >>> On Wed, 11 Nov 2009, Justin Piszcz wrote:
> >>> Again, the problem:
> >>> [    3.318770] cpuidle: using governor ladder
> >>> [    3.321556] ------------[ cut here ]------------
> >>> [    3.321560] WARNING: at arch/x86/kernel/hpet.c:390
> >>> hpet_next_event+0x70/0x80()
> >>> [    3.321561] Hardware name:
> >>> [    3.321562] Modules linked in:
> >>> [    3.321564] Pid: 0, comm: swapper Not tainted 2.6.31.5 #17
> >>> [    3.321565] Call Trace:
> >>> [    3.321567]  [<ffffffff81042f00>] ? hpet_next_event+0x70/0x80
> >>> [    3.321568]  [<ffffffff81042f00>] ? hpet_next_event+0x70/0x80
> >>> [    3.321571]  [<ffffffff81056724>] ? warn_slowpath_common+0x74/0xd0
> >>> [    3.321573]  [<ffffffff81042f00>] ? hpet_next_event+0x70/0x80
> >>> [    3.321576]  [<ffffffff81077696>] ? tick_dev_program_event+0x36/0xb0
> >>> [    3.321578]  [<ffffffff81077079>] ?
> >>> tick_broadcast_oneshot_control+0x119/0x120
> >>> [    3.321579]  [<ffffffff8107683d>] ? tick_notify+0x22d/0x420
> >>> [    3.321581]  [<ffffffff8106fe37>] ? notifier_call_chain+0x37/0x70
> >>> [    3.321583]  [<ffffffff8107612b>] ? clockevents_notify+0x2b/0x90
> >>> [    3.321586]  [<ffffffff81244848>] ? acpi_idle_enter_bm+0x15f/0x2d3
> >>> [    3.321587]  [<ffffffff812446de>] ? acpi_idle_enter_c1+0xf1/0xfc
> >>> [    3.321590]  [<ffffffff812e6d7a>] ? cpuidle_idle_call+0xba/0x120
> >>> [    3.321593]  [<ffffffff8102b832>] ? cpu_idle+0x62/0xc0
> >>> [    3.321596] ---[ end trace cac202f11005305c ]---
> >>> [    3.553852] cpuidle: using governor menu
> >>
> >> Other user with this problem:
> >> http://lkml.org/lkml/2009/10/2/330 - Nobody responded to his report.
> >>
> >> This has been also been reported on other forums with no fix / conclusion on
> >> any type of fix or work-around.
> >
> > Looks like your hpet is busted, or maybe something is resetting the
> > hpet at exactly the wrong time.
> >
> > What does booting with the attached patch do?
> 
> Unfortunately I cannot login fast enough to get a full dmesg:

So if you comment out the printk I added, does it boot?

> It continually scrolls with this:
> 
> [   11.463500] hpet_next_event: hpet_writel failed: 0x9c90955 != 0xa0e8b7b
> [   11.463972] hpet_next_event: hpet_writel failed: 0xa0e8b7b != 0x9cb9398
> [   11.475121] hpet_next_event: hpet_writel failed: 0x9cb9398 != 0xa0e8b71
> [   11.475144] hpet_next_event: hpet_writel failed: 0xa0e8b71 != 0x9ce0459
> [   11.486274] hpet_next_event: hpet_writel failed: 0x9ce0459 != 0xa0e8b61
> [   11.486343] hpet_next_event: hpet_writel failed: 0xa0e8b61 != 0x9d076c0
> [   11.497492] hpet_next_event: hpet_writel failed: 0x9d076c0 != 0xa0e8b4c
> [   11.497962] hpet_next_event: hpet_writel failed: 0xa0e8b4c != 0x9d30119
> [   11.509111] hpet_next_event: hpet_writel failed: 0x9d30119 != 0xa0e8b3c
> [   11.509134] hpet_next_event: hpet_writel failed: 0xa0e8b3c != 0x9d571a9
> [   11.520275] hpet_next_event: hpet_writel failed: 0x9d571a9 != 0xa0e8b2f
> [   11.520293] hpet_next_event: hpet_writel failed: 0xa0e8b2f != 0x9d7e24d
> [   11.531443] hpet_next_event: hpet_writel failed: 0x9d7e24d != 0xa0e8b1d
> [   11.531947] hpet_next_event: hpet_writel failed: 0xa0e8b1d != 0x9da6e46
> [   11.543095] hpet_next_event: hpet_writel failed: 0x9da6e46 != 0xa0e8b0c

Huh. That's sort of crazy. It almost seems as though you have two offset
HPET timers at one timer location that are switching back and forth.
Looks like either very busted hardware, or something new the kernel
doesn't expect.


> When I do not load processor.ko though, the error does not occur?

Hrm. No clue right off.

-john