Subject: Re: Top kernel oopses/warnings for the week of October 7th, 2008

From: "Rafael J. Wysocki" <[email-masked]>
Date: Tue, 7 Oct 2008 22:37:28 +0200

On Tuesday, 7 of October 2008, Ingo Molnar wrote:
> 
> * Rafael J. Wysocki <[email-masked]> wrote:
> 
> > > Rank 9: device_pm_add (warning)
> > > 	Reported 81 times (323 total reports)
> > > 	Drivers with suspect suspend/resume logic; a patch is queued for 2.6.28 to identify
> > > 	which drivers are involved.
> > > 	This warning was last seen in version 2.6.27-rc4, and first seen in 2.6.26-rc5.
> > > 	More info: http://www.kerneloops.org/searchweek.php?search=device_pm_add
> > 
> > This should have been fixed by:
> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f5a6d958b5d0a10e7e7a9dee1862fb31d08c6d26
> 
> hm, that is:
> 
> | From f5a6d958b5d0a10e7e7a9dee1862fb31d08c6d26 Mon Sep 17 00:00:00 2001
> | From: Rafael J. Wysocki <[email-masked]>
> | Date: Sat, 9 Aug 2008 01:05:13 +0200
> | Subject: [PATCH] PM: Remove WARN_ON from device_pm_add
> |
> | PM: Remove WARN_ON from device_pm_add
> |
> | Fix message in device_pm_add() saying that the device will not be
> | added to dpm_list, although in fact the device is going to be added
> | to the list regardless of the ordering violation.
> |
> | Remove the WARN_ON(true) triggered in that situation, because it is
> | hit by USB very often and spams the users' logs.
> |
> | This patch fixes bug #11263
> 
> +               if (dev->parent->power.status >= DPM_SUSPENDING)
> +                       dev_warn(dev, "parent %s should not be sleeping\n",
>                                 dev->parent->bus_id);
> -                       WARN_ON(true);
> -               }
> 
> 
> i.e. no bug was fixed in reality - we still emit a kernel log entry, but 
> the WARN_ON() was removed, so that it does not fall under the scope of 
> kerneloops.org, right?

Sort of.  In fact, the WARN_ON() was added prematurely and caused lots of
unnecessary reports to be generated.

Thanks,
Rafael