Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

dock's uevent reported itself, not ata. It might be difficult to find an
ata device just according to a dock. This patch introduces docking ops
for each device in a dock. when docking, dock driver can send device
specific uevent. This should help dock station too (not just bay)
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

dock driver can handle ata(bay) hotplug now. dock driver already handles
_EJ0 and _STA, so remove them. Also libata doesn't need register
notification handler anymore.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The hotplug notification handler and drivers' notification handler all
run in one workqueue.  Before hotplug removes an acpi device, the
device driver's notification handler is already be recorded to run just
after global notification handler.  After hotplug notification handler
runs, acpica will notice a NULL notification handler and crash.

So now we run run hotplug in another workqueue and wait
for all acpi notication handlers finish.
This was found in battery hotplug, but actually all
hotplug can be affected.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The battery driver already registers notification handler.
To avoid registering notification handler again,
introduce a notifier chain in global system notifier handler
and use it in dock driver.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Make the dock driver support bay and battery hotplug.
They are all regarded as dock, so handling can be unified.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

support _LCK method, which is a optional method for hotplug

lenb: we have not seen _LCK used in the field yet
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

commit 2a7feab28d3fc060d320eaba192e49dad1079b7e introduces a bug.
My thinkpad actually will send an eject_request and we should follow the
eject process to finish the eject, otherwise system still thinks the bay
is present.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

In some BIOSes, every _STA method call will send a notification again,
this cause freeze. And in some BIOSes, it appears _STA should be called
after _DCK. This tries to avoid calls _STA, and still keep the device
present check.

http://bugzilla.kernel.org/show_bug.cgi?id=10431Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

In the function of wait_transaction_complete when the timeout happens,
OS will try to check the status of SMbus again. If the status is what OS
expected, it will be regarded as the bogus timeout. Otherwise it will be
treated as ETIME.

http://bugzilla.kernel.org/show_bug.cgi?id=10483Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
tested-by    : Oldřich Jedlička < <oldium.pro@seznam.cz>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

This fixes a typo in commit 2a2a6471 "Disable MWAIT via DMI on broken Compal board".

It allows the nomwait dmi check to actually detect the Acer 5220.
Signed-off-by: NDennis Jansen <dennis.jansen@web.de>
Tested-by: NDennis Jansen <dennis.jansen@web.de>
Acked-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The early_param handling function could recieve NULL pointer as argument
in case if user didn't enter parameter value.  So we have to be ready for
a such situation and do check for NULL pointer if needed.
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

This fixes a typo in commit 2a2a6471
"Disable MWAIT via DMI on broken Compal board".

It allows the nomwait dmi check to actually detect the Acer 5220.
Signed-off-by: NDennis Jansen <dennis.jansen@web.de>
Tested-by: NDennis Jansen <dennis.jansen@web.de>
Acked-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Signed-off-by: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

The condition is harmless and no need to scare the user

http://bugzilla.kernel.org/show_bug.cgi?id=11245Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Signed-off-by: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Do not use unsigned int if there is test for negative number...

See drivers/acpi/processor_perflib.c
  static unsigned int ignore_ppc = -1;
...
  if (event == CPUFREQ_START && ignore_ppc <= 0) {
       ignore_ppc = 0;
...
Signed-off-by: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

acpi_penalize_isa_irq() should validate irq before using it to
index the acpi_irq_penalty[] table.

Here's the path I'm concerned about:

    pnpacpi_parse_allocated_irqresource()
    {
	...
	irq = acpi_register_gsi(gsi, triggering, polarity);
	if (irq >= 0)
		pcibios_penalize_isa_irq(irq, 1);

There's no guarantee that acpi_register_gsi() will return an IRQ
within the bounds of acpi_irq_penalty[].

I have not seen a failure I can attribute to this.  However,
ACPI_MAX_IRQS is only 256, and I'm pretty sure ia64 can have
IRQs larger than that.

I think this should go in 2.6.27.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

When EC is in Polling mode, OS will check the EC status continually by using
the following source code:
       clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
       while (time_before(jiffies, delay)) {
               if (acpi_ec_check_status(ec, event))
       	            return 0;
               msleep(1);
       }
But msleep is realized by the function of schedule_timeout. At the same time
although one process is already waken up by some events, it won't be scheduled
immediately. So maybe there exists the following phenomena:
     a. The current jiffies is already after the predefined jiffies.
	But before timeout happens, OS has no chance to check the EC
	status again.
     b. If preemptible schedule is enabled, maybe preempt schedule will happen
	before checking loop. When the process is resumed again, maybe
	timeout already happens, which means that OS has no chance to check
	the EC status.

In such case maybe EC status is already what OS expects when timeout happens.
But OS has no chance to check the EC status and regards it as AE_TIME.

So it will be more appropriate that OS will try to check the EC status again
when timeout happens. If the EC status is what we expect, it won't be regarded
as timeout. Only when the EC status is not what we expect, it will be regarded
as timeout, which means that EC controller can't give a response in time.

http://bugzilla.kernel.org/show_bug.cgi?id=9823
http://bugzilla.kernel.org/show_bug.cgi?id=11141Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NZhang Rui  <rui.zhang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

On some ASUS laptops the ECDT gives the incorrect command/status & Data I/O
register address.

AK: it seems like the command/data addresses are exchanged.

In such case it will cause that EC device can't be
initialized correctly.
To add the EC dmi table is to fix this issue. If the laptop falls into the
EC dmi table, the EC command/data I/O address will be fixed.

AK: Add comments describing this better

http://bugzilla.kernel.org/show_bug.cgi?id=9399Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
tested-by    : Jan Kasprzak  <kas@fi.muni.cz>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Some devices emit a ACPI_NOTIFY_DEVICE_CHECK while physically unplugging
even if the software undock has already been done and dock_present() check
fails. However, the internal flags need to be cleared (complete_undock()).

Also, even notify userspace if the dock station suddently went away
without proper software undocking.

This happens on a Acer TravelMate 3000
Signed-off-by: NHolger Macht <hmacht@suse.de>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Trivial cleanups for ACPI. Fix misspelling in printk(), fix mismerge,
add file header.

AK: removed file header
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Although the necessary data structure was set up, it was never actually
passed in, so data block calls have only been working by sheer chance.

(On Acer laptops. the data block methods we've been calling never look at
the instance value, hence acer-wmi never triggered this before).

f3454ae8 brought this to light.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Add error check after all calls to acpi_ns_get_pathname_length.
Add status return from acpi_ns_build_external_path and check after
all calls.  Add parameter validation to acpi_ut_initialize_buffer.

Reported by and initial patch by Ingo Molnar.
http://lkml.org/lkml/2008/7/21/176Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

The DdbHandle returned by Load() does not have its reference count
decremented during unload, leading to a memory leak. Lin Ming.
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Fixes a possible memory leak when thermal and processor objects
are deleted. Any associated notify handlers (and objects) were
not being deleted. Fiodor Suietov. BZ 506

http://www.acpica.org/bugzilla/show_bug.cgi?id=506Signed-off-by: NFiodor Suietov <fiodor.f.suietov@intel.com>
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Some module parameters with only one line have the '\n' at the end of the
description.  This is not needed nor wanted as after the description the
type (i.e.  int) is followed by a newline.

Some modules contain a multi-line description, these are not affected
by this patch.
Signed-off-by: NNiels de Vos <niels.devos@wincor-nixdorf.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Ed L. Cashin <ecashin@coraid.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Roland Dreier <rolandd@cisco.com>
Acked-by: NMauro Carvalho Chehab <mchehab@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NThomas Renninger <trenn@suse.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Ingo Molnar provided a fix to not call _PPC at processor driver
initialization time in "[PATCH] ACPI: fix cpufreq regression" (git
commit e4233dec)

But it can still happen that _PPC is called at processor driver
initialization time.

This patch should make sure that this is not possible anymore.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I get warnings about 'device' possibly being used uninitialised.  While
I can deduce this is not true, it seems that GCC can't.  This patch
changes `check_slot' to return device on success and -1 on error, which
shuts GCC up.
Acked-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pm_idle_save resp. pm_idle_old can be NULL when the restore code in
acpi_processor_cst_has_changed() resp. cpuidle_uninstall_idle_handler()
is called. This can set pm_idle unconditinally to NULL, which causes the
kernel to panic when calling pm_idle in the x86 idle code. This was
covered by an extra check for !pm_idle in the x86 idle code, which was
removed during the x86 idle code refactoring.

Instead of restoring the pm_idle check in the x86 code prevent the
acpi/cpuidle code to set pm_idle to NULL.

Reported by: Dhaval Giani http://lkml.org/lkml/2008/7/2/309
Based on a debug patch from Ingo Molnar
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  * Replace previous instances of the cpumask_of_cpu_ptr* macros
    with a the new (lvalue capable) generic cpumask_of_cpu().
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The acpi idle waits calls local_irq_save and then uses mwait to go into
idle. The tracer gets reenabled at local_irq_save but does not detect that
the idle allows for wake ups.

This patch adds code to disable the tracing when acpi puts the CPU to idle.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There are a few BIOSes that we know of already that need to use the ACPI 1.0
suspend order.  This appears to be only be a small minority of mostly nVidia
based systems.

Based on observation of Windows behaviour, it's clear that Windows is also
doing maintaining its own list of broken hardware that needs this workaround.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Len Brown <lenb@kernel.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ACPI defines a hardware signature.  BIOS calculates the signature according to
hardware configure and if hardware changes while hibernated, the signature
will change.  In that case, S4 resume should fail.

Still, there may be systems on which this mechanism does not work correctly,
so it is better to provide a workaround for them.  For this reason, add a new
switch to the acpi_sleep= command line argument allowing one to disable
hardware signature checking.

[shaohua.li@intel.com: build fix]
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Len Brown <lenb@kernel.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: <Valdis.Kletnieks@vt.edu>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

James Bottomley warns that inclusion of linux/fs.h in a low level
driver was always a danger signal.  This patch moves
memory_read_from_buffer() from fs.h to string.h and fixes includes in
existing memory_read_from_buffer() users.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Bob Moore <robert.moore@intel.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Juha Leppnen noticed that an error path in register_slot() wasn't
returning appropriately, leading to a condition where we might access a
kfree'ed pointer, so let's fix that.

Additionally, fix up the copyright information in the file while
we're in there.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

We have the dev_printk() variants for this kind of thing, use them
instead of directly trying to access the bus_id field of struct device.

This is done in order to remove bus_id entirely.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

-tip testing found the following boot crash on 32-bit x86 (Core2Duo
laptop) yesterday:

[    5.606664] scsi4 : ata_piix
[    5.606664] scsi5 : ata_piix
[    5.606664] ACPI Error (psargs-0358): [\_SB_.PCI0.LPC_.EC__.BSTA] Namespace lookup failure, AE_NOT_FOUND
[    5.606664] ACPI Error (psparse-0530): ACPI Error (nsnames-0186): Invalid NS Node (f7c0e960) while traversing path [20080609]
[    5.606664] BUG: unable to handle kernel NULL pointer dereference at 0000000f
[    5.606664] IP: [<80339e2f>] acpi_ns_build_external_path+0x1f/0x80
[    5.609997] *pdpt = 0000000000a03001 *pde = 0000000000000000
[    5.609997] Oops: 0002 [#1] SMP
[    5.609997]
[    5.609997] Pid: 1, comm: swapper Not tainted (2.6.26-tip-03965-gbbfb62e-dirty #3153)
[    5.609997] EIP: 0060:[<80339e2f>] EFLAGS: 00010286 CPU: 0
[    5.609997] EIP is at acpi_ns_build_external_path+0x1f/0x80
[    5.609997] EAX: f7c18c18 EBX: ffffffff ECX: 00000010 EDX: 00000000
[    5.609997] ESI: f7c18c18 EDI: 00000010 EBP: f7c4dc28 ESP: f7c4dc18
[    5.609997]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[    5.609997] Process swapper (pid: 1, ti=f7c4c000 task=f7c50000 task.ti=f7c4c000)
[    5.609997] Stack: 00000000 00000000 f7c18c18 f7c4dc48 f7c4dc40 80339ed0 00000000 f7c18c18
[    5.609997]        8084c1b6 8084c1b6 f7c4dc58 8033a60a 00000000 00000010 00000000 f7c18c18
[    5.609997]        f7c4dc70 8033a68f f7c18c18 00000000 f6de7600 00000005 f7c4dc98 8033c34d
[    5.609997] Call Trace:
[    5.609997]  [<80339ed0>] ? acpi_ns_handle_to_pathname+0x40/0x72
[    5.609997]  [<8033a60a>] ? acpi_ns_print_node_pathname+0x2c/0x61
[    5.609997]  [<8033a68f>] ? acpi_ns_report_method_error+0x50/0x6d
[    5.609997]  [<8033c34d>] ? acpi_ps_parse_aml+0x149/0x2f9
[    5.609997]  [<8033d6dd>] ? acpi_ps_execute_method+0x132/0x201
[    5.609997]  [<80339d19>] ? acpi_ns_evaluate+0x1ad/0x258
[    5.609997]  [<803406c4>] ? acpi_ut_evaluate_object+0x55/0x18f
[    5.609997]  [<803408b7>] ? acpi_ut_execute_STA+0x22/0x7a
[    5.609997]  [<8033a907>] ? acpi_get_object_info+0x131/0x1be
[    5.609997]  [<80344bb2>] ? do_acpi_find_child+0x22/0x4b
[    5.609997]  [<8033b855>] ? acpi_ns_walk_namespace+0xa5/0x124
[    5.609997]  [<803394f3>] ? acpi_walk_namespace+0x54/0x74
[    5.609997]  [<80344b90>] ? do_acpi_find_child+0x0/0x4b
[    5.609997]  [<80344b85>] ? acpi_get_child+0x38/0x43
[    5.609997]  [<80344b90>] ? do_acpi_find_child+0x0/0x4b
[    5.609997]  [<804d0148>] ? ata_acpi_associate+0xb5/0x1b5
[    5.609997]  [<804c6ecb>] ? ata_scsi_add_hosts+0x8e/0xdc
[    5.609997]  [<804c40c8>] ? ata_host_register+0x9f/0x1d6
[    5.609997]  [<804cbc7f>] ? ata_pci_sff_activate_host+0x179/0x19f
[    5.609997]  [<804cdd45>] ? ata_sff_interrupt+0x0/0x1c7
[    5.609997]  [<8069b033>] ? piix_init_one+0x569/0x5b0
[    5.609997]  [<801bd400>] ? sysfs_ilookup_test+0x0/0x11
[    5.609997]  [<801987d7>] ? ilookup5_nowait+0x29/0x30
[    5.609997]  [<802efc7e>] ? pci_match_device+0x99/0xa3
[    5.609997]  [<802efd3c>] ? pci_device_probe+0x39/0x59
[    5.609997]  [<803bc4af>] ? driver_probe_device+0xa0/0x11b
[    5.609997]  [<803bc564>] ? __driver_attach+0x3a/0x59
[    5.609997]  [<803bbde3>] ? bus_for_each_dev+0x36/0x58
[    5.609997]  [<803bc354>] ? driver_attach+0x14/0x16
[    5.609997]  [<803bc52a>] ? __driver_attach+0x0/0x59
[    5.609997]  [<803bc161>] ? bus_add_driver+0x93/0x196
[    5.609997]  [<803bc773>] ? driver_register+0x71/0xcd
[    5.609997]  [<802eff05>] ? __pci_register_driver+0x3f/0x6e
[    5.609997]  [<809af7ff>] ? piix_init+0x14/0x24
[    5.609997]  [<80984568>] ? kernel_init+0x128/0x269
[    5.609997]  [<809af7eb>] ? piix_init+0x0/0x24
[    5.609997]  [<802e2758>] ? trace_hardirqs_on_thunk+0xc/0x10
[    5.609997]  [<80116aef>] ? restore_nocheck_notrace+0x0/0xe
[    5.609997]  [<80984440>] ? kernel_init+0x0/0x269
[    5.609997]  [<80984440>] ? kernel_init+0x0/0x269
[    5.609997]  [<80117d87>] ? kernel_thread_helper+0x7/0x10
[    5.609997]  =======================
[    5.609997] Code: 75 02 b3 01 8d 43 01 8b 5d fc c9 c3 55 89 e5 57 89 cf 56 53 89 d3 4b 83 ec 04 83 fb 03 89 55 f0 77 09 c6 01 5c c6 41 01 00 eb 59 <c6> 04 19 00 8b 55 f0 8d 34 11 89 c2 eb 19 8b 42 08 83 eb 05 89
[    5.609997] EIP: [<80339e2f>] acpi_ns_build_external_path+0x1f/0x80 SS:ESP 0068:f7c4dc18
[    5.613331] Kernel panic - not syncing: Fatal exception
[    5.613331] Rebooting in 1 seconds..[    4.646664] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)

I have bisected it down to:

 # bad:  [5b664cbe] Merge branch 'upstream-linus' of git://git.kernel.
 # good: [bce7f795] Linux 2.6.26
 # good: [e18425ab] Merge branch 'tracing/for-linus' of git://git.kern
 # good: [cadc7236] Merge branch 'bkl-removal' into next
 # good: [4515889a] Merge branch 'merge' of git://git.kernel.org/pub/s
 # good: [42fdd14e] Merge git://git.kernel.org/pub/scm/linux/kernel/gi
 # good: [8a0ca91f] Merge branch 'for-linus' of git://git.kernel.org/p
 # bad:  [0af4b8cb] ACPI: Introduce new device wakeup flag 'prepared'
 # good: [fe997407] PCI: construct one fakephp slot per PCI slot
 # bad:  [531f254a] PCIE: aer: use dev_printk when possible
 # bad:  [15650a20] x86/PCI: fixup early quirk probing
 # good: [0e6859d9] ACPI PM: Remove obsolete Toshiba workaround
 # bad:  [8344b566] PCI: ACPI PCI slot detection driver
 # good: [f46753c9] PCI: introduce pci_slot

 | 8344b568 is first bad commit
 | commit 8344b568
 | Author: Alex Chiang <achiang@hp.com>
 | Date:   Tue Jun 10 15:30:42 2008 -0600
 |
 |     PCI: ACPI PCI slot detection driver
 |
 |     Detect all physical PCI slots as described by ACPI, and create entries in
 |     /sys/bus/pci/slots/.

I.e. the new CONFIG_ACPI_PCI_SLOT=y option was causing this crash.

But the bug is not mainly in this new PCI code - that code was just
hitting the ACPI code in a new way which made ACPI break.

The crash signature shows that we are crashing on this instruction:

   movb $0x0, (%ecx, %ebx, 1)

ECX and EBX are 0x10 and -1. It's this line in
drivers/acpi/namespace/nsnames.c's acpi_ns_build_external_path():

        name_buffer[index] = 0;

I.e. name_buffer is 0x10 and index is -1.

index -1 corresponds to size 0, and name_buffer 0x10 is slab's
ZERO_SIZE_PTR special-case for zero-sized allocations.

I.e. when we called acpi_ns_handle_to_pathname(), we got required_size
of 0 due to an error condition, but this is passed to the ACPI allocator
unconditionally:

        required_size = acpi_ns_get_pathname_length(node);

        /* Validate/Allocate/Clear caller buffer */

        status = acpi_ut_initialize_buffer(buffer, required_size);
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }

Where acpi_ut_initialize_buffer(), through many (unnecessary) layers,
ends up calling kzalloc(0). Which returns 0x10 and that then causes the
crash later on.

So fix both callers of acpi_ns_get_pathname_length(), which can return 0
in case of an invalid node.

Also add a WARN_ON() against zero sized allocations in
acpi_ut_initialize_buffer() to make it easier to find similar instances
of this bug.

I have tested this patch for the past 24 hours and the crash has not
reappeared.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

commit d1857056 ("ACPI: don't walk
tables if ACPI was disabled") is another superfluous duplicate commit
caused by git -> quilt -> git conversion.

Revert it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>