Re: v2.6.23-rc2 locks up during boot (without acpi=off)

["Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>]

On Sun, 12 Aug 2007, Andrew Morton wrote:

> On Sun, 12 Aug 2007 14:20:46 +0300 (EEST) "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi> wrote:
> > On Sun, 12 Aug 2007, Andrew Morton wrote:
> > > On Sat, 11 Aug 2007 15:39:30 +0300 (EEST) "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi> wrote:
> > > 
> > > > I noticed that v2.6.23-rc1 locks up during boot, same thing happens now 
> > > > with the latest linus' tree (+net-2.6.24 and tcp-2.6 tree stuff on top 
> > > > of it; in -rc1 test they weren't though). The exact location of hang
> > > > varies a bit though. No OOPS, does not respond to sysrq or anything else 
> > > > besides reset. Last known bootable one is something like 2.6.22-rc4 
> > > > (I usually run 2.6.21.5 on this machine, haven't tried any 2.6.22 on
> > > > this after those rcs). Problem seems to start after this line:
> > > > 
> > > > Time: acpi_pm clocksource has been installed.
> > > > 
> > > > ...the power led starts blinking (not periodic cycle but more or less 
> > > > varying on-off cycle, never seen that led blink before at all, didn't know 
> > > > that one can make it blink :-)) and the machine gets consideably slower 
> > > > too. Never have it been able to complete booting all they way up to login 
> > > > prompt before lock up.
> > > > 
> > > > Tried with acpi=off, boots just fine.
> > >
> > > It'd be great if you could run a git bisection search please.
> > 
> > [...snip...]
> > 
> > ...didn't bother to go any further as the other one just deals with printk 
> > string... So this is the main suspect:
> > 
> > commit 18eab8550397f1f3d4b8b2c5257c88dae25d58ed
> > Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
> > Date:   Fri Jun 15 19:37:00 2007 -0400
> > 
> >     ACPI: Enable C3 even when PM2_control is zero
> >     
> >     On systems that do not have pm2_control_block, we cannot really use
> >     ARB_DISABLE before C3. We used to disable C3 totally on such systems.
> >     
> >     To be compatible with Windows, we need to enable C3 on such systems now.
> >     We just skip ARB_DISABLE step before entering the C3-state and assume
> >     hardware is handling things correctly. Also, ACPI spec is not clear
> >     about pm2_control is _needed_ for C3 or not.
> >     
> >     We have atleast one system that need this to enable C3.
> >     
> >     Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
> >     Signed-off-by: Len Brown <len.brown@intel.com>
> > 
> 
> OK, that's great, thanks.  So just to double-check, could you please
> confirm that the below reversion fixes this post-2.6.22 regression?

Hmm, it was really worth of it, I did:
$ git-fetch linus
$ git-reset --hard linus
[...make & install & boot...]

...and voila, the problem went away, so something else seems to have
fixed it between: ac07860264bd and 963c6527e0a0e. As you can notice,
I didn't even have to revert it (I was just double checking current
mainline first).

Is there a need to get a more detailed view about the cause or something, 
or are details of this issue clear enough to everyone? I can do some more 
research if necessary, though expect a bit longer latencies during the 
next week...

In case none, thanks everyone, this issue seems solved. :-)

-- 
 i.