Re: [PATCH] PM: acquire device locks prior to suspending

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 14 Dec 2007 01:08:37 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> On Thursday, 13 of December 2007, Rafael J. Wysocki wrote:
> > On Thursday, 13 of December 2007, Andrew Morton wrote:
> > > On Fri, 21 Sep 2007 15:37:40 -0400 (EDT) Alan Stern <stern@rowland.harvard.edu> wrote:
> > > 
> > > > This patch (as994) reorganizes the way suspend and resume
> > > > notifications are sent to drivers.  The major changes are that now the
> > > > PM core acquires every device semaphore before calling the methods,
> > > > and calls to device_add() during suspends will fail.
> > > 
> > > Causes my t61p to deadlock during suspend-to-RAM.  Really late - the little
> > > moon symbol has started to flash but the LCD is still powered and the
> > > cursor still blinks.  Only a poweroff restores control.
> > 
> > Most probably, one of the drivers or a CPU hotplug notifier unregisters a
> > device during suspend (wrong).
> > 
> > Please boot with no_console_suspend and check if the box survives (with this
> > patch applied):
> > 
> > # echo 8 > /proc/sys/kernel/printk
> > # echo processors > /sys/power/pm_test
> > # echo mem > /sys/power/state
> > 
> > If it doesn't, you can try 
> > 
> > # echo platform > /sys/power/pm_test
> > # echo mem > /sys/power/state
> > 
> > and
> > 
> > # echo devices > /sys/power/pm_test
> > # echo mem > /sys/power/state
> 
> Ah, that won't work, because git-acpi-build-fix.patch killed
> /sys/power/pm_test altogether.  Sorry.

I was wondering..

What's going on with git-acpi-build-fix.patch anyway?  Is there
something different we should do?