This was marked incorrectly for some reason. Allow the ibmphp driver to
be built even if PCI_LEGACY is not enabled.
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This removes the depandancy of the cpcihp driver from the PCI_LEGACY
config option by removing its usage of the pci_find_bus() function.
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Scott Murray <scottm@somanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This cleans up the search.c file, now using the pci list of devices that
are created for the driver core, instead of relying on our separate list
of devices. It's better to use the functions already created for this
kind of thing, instead of rolling our own all the time.
This work is done in anticipation of getting rid of that second list of
pci devices all together.
And it ends up saving code, always a nice benefit.
This also removes one compiler warning for when CONFIG_PCI_LEGACY is
enabled as we no longer internally use the deprecated functions anymore.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This removes the pci_get_device_reverse function as there should not be
any need to walk pci devices backwards anymore. All users of this call
are now gone from the tree, so it is safe to remove it.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No one is using this function anymore for quite some time, so remove it.
Everyone calls pci_dev_present() instead anyway...
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
An unused function that bloated the kernel only when CONFIG_EMBEDDED was
enabled...
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 3c0a654e39 and
fixes kernel bug #10245:
http://bugzilla.kernel.org/show_bug.cgi?id=10245
The HP Compaq nc6120 has the same PCI sub-device ID as the nx6110, and the
SMBus is used by ACPI for thermal management on the nc6120, so Linux should
not attach a native driver to it. This means that this quirk is unsafe and
has to be removed.
I also added a comment to help developers realize that adding new IDs to this
SMBus unhiding quirk table should be done only with great care, and in
particular only after checking that ACPI is not making use of the SMBus.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Tomasz Koprowski <tomek@koprowski.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 8fa5913d54, which
caused various interesting problems for people, including wrong resource
allocations. See for example bugzilla entry "2.6.25-rc2: ohci1394
problem (MMIO broken)" at
http://bugzilla.kernel.org/show_bug.cgi?id=10080
And Gary Hade says:
"The same change had also exposed an issue reported by Paul Martin that
has been causing an Oops while hotplugging ThinkPads to a ThinkPad
Dock II. See
http://lkml.org/lkml/2008/2/19/405http://bugzilla.kernel.org/show_bug.cgi?id=9961
I have a fix for the ThinkPad docking Oops but if the issue being
discussed here is caused by the transparent bridge sizing removal
change I totally agree that it should be reverted."
The transparent bridge sizing removal change was motivated by
insufficient PCI memory resource for a transparent bridge window that
was being created as a result of expansion ROM(s) being included in
the transparent bridge sizing calculations.
A later "PCI: Remove default PCI expansion ROM memory allocation"
change ( re: http://lkml.org/lkml/2007/12/11/361 ) removes the
expansion ROM(s) from the transparent bridge sizing calculations which
actually resolves the original issue in a different manner. So, even
if the "PCI: remove transparent bridge sizing" is not problematic it
is no longer needed anyway."
Identified-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Tested-by: Thomas Meyer <thomas@m3y3r.de>
Acked-by: Gary Hade <garyhade@us.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert as it is reported to cause problems for people.
commit 4348a2dc49
Author: Shaohua Li <shaohua.li@intel.com>
Date: Wed Oct 24 10:45:08 2007 +0800
pcie: utilize pcie transaction pending bit
PCIE has a mechanism to wait for Non-Posted request to complete. I think
pci_disable_device is a good place to do this.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Due to the regression reported at
http://bugzilla.kernel.org/show_bug.cgi?id=10065
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Soeren Sonnenburg <kernel@nn7.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
lockdep goes off on the iova copy_reserved_iova() because it and a function
it calls grabs locks in the from, and the to of the copy operation.
The function grab locks of the same lock classes triggering the warning. The
first lock grabbed is for the constant reserved areas that is never accessed
after early boot. Technically you could do without grabbing the locks for the
"from" structure its copying reserved areas from.
But dropping the from locks to me looks wrong, even though it would be ok.
The affected code only runs in early boot as its setting up the DMAR
engines.
This patch gives the reserved_ioval_list locks special lockdep classes.
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes a 2.6.25 regression reported by Alex Chiang.
Invoke pciehp_enable_slot() at startup only when pciehp_force=1.
Some HP equipment apparently cannot cope with it otherwise.
This restores the (previously working) 2.6.24 behaviour here,
while allowing machines that need a kick to use pciehp_force=1.
This was the original design back in October 2007,
but Kristen suggested we try without it first:
Kristen Carlson Accardi wrote:
>I think it would be ok to try allowing the slot to be enabled when not
>using pciehp_force mode. We can wrap it later if it proves to break things
This ended up breaking one of Alex's setups,
so it's time to put the wrapper back in now.
Signed-off-by: Mark Lord <mlord@pobox.com>
Acked-by: Alex Chiang <achiang@hp.com>
Acked-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PCI busses can be registered multiple times, so we need to detect if we
have registered our bus structure in sysfs already. If so, don't do it
again.
Thanks to Guennadi Liakhovetski <g.liakhovetski@gmx.de> for reporting
the problem, and to Linus for poking me to get me to believe that it was
a real problem.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In drivers/pci/hotplug/ibmphp_ebda.c::ebda_rsrc_controller(), storage is
allocated with kzalloc() and assigned to 'tmp_slot'. Then lots of
stuff, like ->flag, ->supported_speed etc is set in tmp_slot. A bit
further down there's then this test :
if (!bus_info_ptr1) {
rc = -ENODEV;
goto error;
}
At this point, tmp_slot has not been assigned to anything, so when
erroring-out we want to free it, but nothing at the 'error:' label
free's 'tmp_slot' - and we can't really free 'tmp_slot' at 'error:'
since we may jump to that label later when 'tmp_slot' *has* been used
and we do not want it freed. So, the only sane option left seems to be
to kfree(tmp_slot) just before jumping to the 'error:' label in the one
place where this is what actually makes sense. The following patch does
just that and thus kills off a tiny potential memory leak.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix the error code path in hpc_power_off_slot().
The Bad DLLP Mask bit must be restored before return.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Due to the class_device cleanup of pci_bus, the error messages when
things go wrong are incorrect. So fix this up to properly report what
is really happening, if things go wrong.
Thanks to Kay for pointing out the issue.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix following warning:
WARNING: vmlinux.o(.text+0x47bdb1): Section mismatch in reference from the function pci_scan_child_bus() to the function .devinit.text:pcibios_fixup_bus()
We had plenty of functions that could be annotated __devinit but due to
the former restriction that exported symbols could not be annotated
they were not so. So annotate these function and fix the references
from the pci/hotplug/* code to silence the resuting warnings.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix docbook problems in kernel-api.tmpl.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following is a clean up and correction of the copyright holding
entities for the files associated with the intel iommu code.
Signed-off-by: <mgross@linux.intel.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During the last step of hibernation in the "platform" mode (with the
help of ACPI) we use the suspend code, including the devices'
->suspend() methods, to prepare the system for entering the ACPI S4
system sleep state.
But at least for some devices the operations performed by the
->suspend() callback in that case must be different from its operations
during regular suspend.
For this reason, introduce the new PM event type PM_EVENT_HIBERNATE and
pass it to the device drivers' ->suspend() methods during the last phase
of hibernation, so that they can distinguish this case and handle it as
appropriate. Modify the drivers that handle PM_EVENT_SUSPEND in a
special way and need to handle PM_EVENT_HIBERNATE in the same way.
These changes are necessary to fix a hibernation regression related
to the i915 driver (ref. http://lkml.org/lkml/2008/2/22/488).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minor cleanups to acpi_pci_set_power_state(): use the ACPI and PCI
state symbols to make clear that a mapping is being done between PCI
and ACPI states, instead of using magic numbers. For paranoia's sake,
report any errors. Save five bytes (x86_64) too.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix wrong counter check for proc_dir_entry in pci_proc_detach_device().
The pci_proc_detach_device() returns with -EBUSY before calling
remove_proc_entry() if the reference counter of proc_dir_entry is not
0. But this check is wrong and pci_proc_detach_device() always fails
because the reference counter of proc_dir_entry is initialized with 1
at creating time and decremented in remove_proc_entry(). This bug
cause strange behaviour as followings:
- Accessing /proc/bus/pci/XXXX/YY file after hot-removing pci adapter
card causes kernel panic.
- Repeating hot-add/hot-remove of pci adapter card increases files
with the same name under /proc/bus/pci/XXXX/ directory. For example:
# pwd
/proc/bus/pci/0002:09
# ls
01.0
# for i in `seq 5`
> do
> echo 0 > /sys/bus/pci/slots/0009_0032/power
> echo 1 > /sys/bus/pci/slots/0009_0032/power
> done
# ls
01.0 01.0 01.0 01.0 01.0 01.0
The pci_proc_detach_device() should check if the reference counter is
not larger than 1 instead.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use upper_32_bits(): no code changes, one less ifdef.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
According to HT spec, to get message interrupt from devices mapped to HT
interrupt message, the 'En' bit of MSI Mapping capability need to be set.
The patch do this setting in quirks code for the devices on HT-based nvidia
platform.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andy Currid <acurrid@nvidia.com>
Signed-off-by: Peer Chen <pchen@nvidia.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix PCI kernel-doc warning:
Warning(linux-2.6.24-git12//drivers/pci/pci-acpi.c:166): No description found for parameter 'hid'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
PCI: modify SATA IDE mode quirk
When initialize and resume, SB600/700/800 need to set SATA mode
correctly.
Signed-off-by: Crane Cai <crane.cai@amd.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/pci/hotplug/acpiphp_ibm.c:ibm_find_acpi_device() is not
large enough to accommodate data returned by the _CID method
executed from acpi_get_object_info().
This patch eliminates the problem by letting ACPI code
(instead of driver code) determine and obtain a correctly
sized buffer.
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The last line of the comment preceding the definition of
acpi_pci_choose_state() is incorrect. Remove it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix PCI kernel-doc warning:
Warning(linux-2.6.24-git12//drivers/pci/pci-acpi.c:166): No description found for parameter 'hid'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
kernel.
This patch also adds board support for the ASB2303 with the ASB2308 daughter
board, and the ASB2305. The only processor supported is the MN103E010, which
is an AM33v2 core plus on-chip devices.
[akpm@linux-foundation.org: nuke cvs control strings]
Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com>
Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix an off by one bug in the fault reason string reporting function, and
clean up some of the code around this buglet.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for protected memory enable bits by clearing them if they are
set at startup time. Some future boot loaders or firmware could have this
bit set after it loads the kernel, and it needs to be cleared if DMA's are
going to happen effectively.
Signed-off-by: mark gross <mgross@intel.com>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I would like to potentially move the sparc64 IOMMU code over to using
the nice new drivers/pci/iova.[ch] code for free area management..
In order to do that we have to detach the IOMMU page size assumptions
which only really need to exist in the intel-iommu.[ch] code.
This patch attempts to implement that.
[akpm@linux-foundation.org: build fix]
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds PCI's accessor for segment_boundary_mask in device_dma_parameters.
The default segment_boundary is set to 0xffffffff, same to the block layer's
default value (and the scsi mid layer uses the same value).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Greg KH <greg@kroah.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds struct device_dma_parameters in struct pci_dev and properly
sets up a pointer in struct device.
The default max_segment_size is set to 64K, same to the block layer's
default value.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Mostly-acked-by: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following warnings were issued during build of
drivers/pci with an allyesconfig build:
WARNING: o-x86_64/drivers/pci/built-in.o(.text+0xdaf): Section mismatch in reference from the function pci_add_new_bus() to the function .devinit.text:pci_alloc_child_bus()
WARNING: o-x86_64/drivers/pci/built-in.o(.text+0x15e2): Section mismatch in reference from the function pci_scan_single_device() to the function .devinit.text:pci_scan_device()
WARNING: o-x86_64/drivers/pci/built-in.o(.text+0x1b0c5): Section mismatch in reference from the function pci_bus_assign_resources() to the function .devinit.text:pci_setup_bridge()
WARNING: o-x86_64/drivers/pci/built-in.o(.text+0x1b32d): Section mismatch in reference from the function pci_bus_size_bridges() to the function .devinit.text:pci_bus_size_cardbus()
Investigating each case closer it looked like all
referred functions are only used in the init phase
or during hotplug.
So to avoid wasting too much memory in the non-hotplug
case the simpler fix was to allow the fuctions to
use code/data from the __devinit sections.
This was done in all four case by adding the __ref
annotation.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix following warnings:
WARNING: o-x86_64/drivers/pci/built-in.o(.text+0xb054): Section mismatch in reference from the function cpci_configure_slot() to the function .devinit.text:pci_do_scan_bus()
WARNING: o-x86_64/drivers/pci/built-in.o(.text+0x153ab): Section mismatch in reference from the function shpchp_configure_device() to the function .devinit.text:pci_do_scan_bus()
WARNING: o-x86_64/drivers/pci/built-in.o(__ksymtab+0xc0): Section mismatch in reference from the variable __ksymtab_pci_do_scan_bus to the function .devinit.text:pci_do_scan_bus()
PCI hotplug were the only user of pci_do_scan_bus()
so moving this function to a separate file that is build
only when we enable CONFIG_HOTPLUG_PCI.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 6c723d5bd8.
It caused build errors on non-x86 platforms, config file confusion, and
even some boot errors on some x86-64 boxes. All around, not quite ready
for prime-time :(
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6: (64 commits)
PCI: make pci_bus a struct device
PCI: fix codingstyle issues in include/linux/pci.h
PCI: fix codingstyle issues in drivers/pci/pci.h
PCI: PCIE ASPM support
PCI: Fix fakephp deadlock
PCI: modify SB700 SATA MSI quirk
PCI: Run ACPI _OSC method on root bridges only
PCI ACPI: AER driver should only register PCIe devices with _OSC
PCI ACPI: Added a function to register _OSC with only PCIe devices.
PCI: constify function pointer tables
PCI: Convert drivers/pci/proc.c to use unlocked_ioctl
pciehp: block new requests from the device before power off
pciehp: workaround against Bad DLLP during power off
pciehp: wait for 1000ms before LED operation after power off
PCI: Remove pci_enable_device_bars() from documentation
PCI: Remove pci_enable_device_bars()
PCI: Remove users of pci_enable_device_bars()
PCI: Add pci_enable_device_{io,mem} intefaces
PCI: avoid save the same type of cap multiple times
PCI: correctly initialize a structure for pcie_save_pcix_state()
...
This moves the pci_bus class device to be a real struct device and at
the same time, place it in the device tree in the correct location.
Note, the old "bridge" symlink is now gone, but this was a non-standard
link and no userspace program used it. If you need to determine the
device that the bus is on, follow the standard device symlink, or walk
up the device tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state
and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If the fakephp driver is used to emulate removal of a PCI device by
writing text string "0" to the "power" sysfs attribute file, this causes
its parent directory and its contents (including the "power" file) to be
deleted before the write operation returns. Unfortunately, it ends up
in a deadlock waiting for itself to complete.
The deadlock is as follows: sysfs_write_file calls flush_write_buffer
which calls sysfs_get_active_two before calling power_write_file in
pci_hotplug_core.c via the sysfs store operation. The power_write_file
function calls disable_slot in fakephp.c via the slot operation. The
disable_slot function calls remove_slot which calls pci_hp_deregister
(back in pci_hotplug_core.c) which calls fs_remove_slot which calls
sysfs_remove_file to remove the "power" file. The sysfs_remove_file
function calls sysfs_hash_and_remove which calls sysfs_addrm_finish
which calls sysfs_deactivate. The sysfs_deactivate function sees that
something has an active reference on the sysfs_dirent (from the
previous call to sysfs_get_active_two back up the call stack somewhere)
so waits for the active reference to go away, which is of course
impossible.
The problem has been present since 2.6.21.
This patch breaks the deadlock by queuing work queue items on a single-
threaded work queue to remove a slot from sysfs, and to rescan the PCI
buses. There is also some protection against disabling a slot that is
already being removed.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
