On Fri, 2008-08-15 at 04:56 +0200, Andi Kleen wrote:

Greg KH wrote:

quoted

On Thu, Aug 14, 2008 at 08:38:28AM -0700, Randy Dunlap wrote:

quoted

calling  param_sysfs_init+0x0/0x1e7
------------[ cut here ]------------
WARNING: at fs/sysfs/dir.c:463 sysfs_add_one+0x35/0x3d()
sysfs: duplicate filename 'acpi' can not be created

Why would this be a sysfs error, it's acpi doing something foolish,
that's why the sysfs layer is warning about it :)

The NULL pointer reference further down actually looks like something
foolish in the sysfs layer. But actually ACPI is not doing
anything wrong here I think. According to the backtrace it happens
when a kernel param (aka module_param) is set. And creating multiple
params in the same acpi space is completely legal.

It looks more like the high level code that sets up these parameters
broke somehow and starts registering these twice and now ACPI is the
first one to hit it (maybe because it starts with 'a' :-). 

Perhaps we could try "acpi=off" and see if it still happens.

thanks,
rui