linux-stable.git/drivers/pci/remove.c, branch linux-3.13.y

PCI: Move device_del() from pci_stop_dev() to pci_destroy_dev()

2013-11-25T21:39:58+00:00

After commit bcdde7e221a8 (sysfs: make __sysfs_remove_dir() recursive)
I'm seeing traces analogous to the one below in Thunderbolt testing:

WARNING: CPU: 3 PID: 76 at /scratch/rafael/work/linux-pm/fs/sysfs/group.c:214 sysfs_remove_group+0x59/0xe0()
 sysfs group ffffffff81c6c500 not found for kobject '0000:08'
 Modules linked in: ...
 CPU: 3 PID: 76 Comm: kworker/u16:7 Not tainted 3.13.0-rc1+ #76
 Hardware name: Acer Aspire S5-391/Venus    , BIOS V1.02 05/29/2012
 Workqueue: kacpi_hotplug acpi_hotplug_work_fn
  0000000000000009 ffff8801644b9ac8 ffffffff816b23bf 0000000000000007
  ffff8801644b9b18 ffff8801644b9b08 ffffffff81046607 ffff88016925b800
  0000000000000000 ffffffff81c6c500 ffff88016924f928 ffff88016924f800
 Call Trace:
  [] dump_stack+0x4e/0x71
  [] warn_slowpath_common+0x87/0xb0
  [] warn_slowpath_fmt+0x41/0x50
  [] ? sysfs_get_dirent_ns+0x6f/0x80
  [] sysfs_remove_group+0x59/0xe0
  [] dpm_sysfs_remove+0x3b/0x50
  [] device_del+0x58/0x1c0
  [] device_unregister+0x48/0x60
  [] pci_remove_bus+0x6e/0x80
  [] pci_remove_bus_device+0x38/0x110
  [] pci_remove_bus_device+0x4d/0x110
  [] pci_stop_and_remove_bus_device+0x19/0x20
  [] disable_slot+0x20/0xe0
  [] acpiphp_check_bridge+0xa8/0xd0
  [] hotplug_event+0x17d/0x220
  [] hotplug_event_work+0x30/0x70
  [] acpi_hotplug_work_fn+0x18/0x24
  [] process_one_work+0x261/0x450
  [] worker_thread+0x21e/0x370
  [] ? rescuer_thread+0x300/0x300
  [] kthread+0xd2/0xe0
  [] ? flush_kthread_worker+0x70/0x70
  [] ret_from_fork+0x7c/0xb0
  [] ? flush_kthread_worker+0x70/0x70

(Mika Westerberg sees them too in his tests).

Some investigation documented in kernel bug #65281 led me to the
conclusion that the source of the problem is the device_del() in
pci_stop_dev() as it now causes the sysfs directory of the device to be
removed recursively along with all of its subdirectories.  That includes
the sysfs directory of the device's subordinate bus (dev->subordinate) and
its "power" group.

Consequently, when pci_remove_bus() is called for dev->subordinate in
pci_remove_bus_device(), it calls device_unregister(&bus->dev), but at this
point the sysfs directory of bus->dev doesn't exist any more and its
"power" group doesn't exist either.  Thus, when dpm_sysfs_remove() called
from device_del() tries to remove that group, it triggers the above
warning.

That indicates a logical mistake in the design of
pci_stop_and_remove_bus_device(), which causes bus device objects to be
left behind their parents (bridge device objects) and can be fixed by
moving the device_del() from pci_stop_dev() into pci_destroy_dev(), so
pci_remove_bus() can be called for the device's subordinate bus before the
device itself is unregistered from the hierarchy.  Still, the driver, if
any, should be detached from the device in pci_stop_dev(), so use
device_release_driver() directly from there.

References: https://bugzilla.kernel.org/show_bug.cgi?id=65281#c6
Reported-by: Mika Westerberg 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas

PCI: Fix whitespace, capitalization, and spelling errors

2013-11-14T18:28:18+00:00

Fix whitespace, capitalization, and spelling errors.  No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska  (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki

PCI: Add pcibios hooks for adding and removing PCI buses

2013-04-12T21:38:25+00:00

On ACPI-based platforms, the pci_slot driver creates PCI slot devices
according to information from ACPI tables by registering an ACPI PCI
subdriver.  The ACPI PCI subdriver will only be called when creating/
destroying PCI root buses, and it won't be called when hot-plugging
P2P bridges.  It may cause stale PCI slot devices after hot-removing
a P2P bridge if that bridge has associated PCI slots.  And the acpiphp
driver has the same issue too.

This patch introduces two hook points into the PCI core, which will
be invoked when creating/destroying PCI buses for PCI host and P2P
bridges.  They could be used to setup/destroy platform dependent stuff
in a unified way, both at boot time and for PCI hotplug operations.

Signed-off-by: Jiang Liu 
Signed-off-by: Yijing Wang 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Yinghai Lu 
Cc: "Rafael J. Wysocki" 
Cc: Toshi Kani 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Myron Stowe

PCI: When removing bus, always remove legacy files & unregister

2013-04-12T20:57:02+00:00

We always call device_register() and pci_create_legacy_files() for a
new bus before handing out the "struct pci_bus *".  Therefore, there's
no possiblity of removing the bus with pci_remove_bus() before those
calls have been made, so we don't need to check "bus->is_added" before
calling pci_remove_legacy_files() and device_unregister().

[bhelgaas: changelog]
Signed-off-by: Jiang Liu 
Signed-off-by: Yijing Wang 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Yinghai Lu 
Cc: "Rafael J. Wysocki" 
Cc: Toshi Kani

Merge tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2013-02-26T05:18:18+00:00

Pull PCI changes from Bjorn Helgaas:
 "Host bridge hotplug
    - Major overhaul of ACPI host bridge add/start (Rafael Wysocki, Yinghai Lu)
    - Major overhaul of PCI/ACPI binding (Rafael Wysocki, Yinghai Lu)
    - Split out ACPI host bridge and ACPI PCI device hotplug (Yinghai Lu)
    - Stop caching _PRT and make independent of bus numbers (Yinghai Lu)

  PCI device hotplug
    - Clean up cpqphp dead code (Sasha Levin)
    - Disable ARI unless device and upstream bridge support it (Yijing Wang)
    - Initialize all hot-added devices (not functions 0-7) (Yijing Wang)

  Power management
    - Don't touch ASPM if disabled (Joe Lawrence)
    - Fix ASPM link state management (Myron Stowe)

  Miscellaneous
    - Fix PCI_EXP_FLAGS accessor (Alex Williamson)
    - Disable Bus Master in pci_device_shutdown (Konstantin Khlebnikov)
    - Document hotplug resource and MPS parameters (Yijing Wang)
    - Add accessor for PCIe capabilities (Myron Stowe)
    - Drop pciehp suspend/resume messages (Paul Bolle)
    - Make pci_slot built-in only (not a module) (Jiang Liu)
    - Remove unused PCI/ACPI bind ops (Jiang Liu)
    - Removed used pci_root_bus (Bjorn Helgaas)"

* tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits)
  PCI/ACPI: Don't cache _PRT, and don't associate them with bus numbers
  PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGS
  ACPI / PCI: Make pci_slot built-in only, not a module
  PCI/PM: Clear state_saved during suspend
  PCI: Use atomic_inc_return() rather than atomic_add_return()
  PCI: Catch attempts to disable already-disabled devices
  PCI: Disable Bus Master unconditionally in pci_device_shutdown()
  PCI: acpiphp: Remove dead code for PCI host bridge hotplug
  PCI: acpiphp: Create companion ACPI devices before creating PCI devices
  PCI: Remove unused "rc" in virtfn_add_bus()
  PCI: pciehp: Drop suspend/resume ENTRY messages
  PCI/ASPM: Don't touch ASPM if forcibly disabled
  PCI/ASPM: Deallocate upstream link state even if device is not PCIe
  PCI: Document MPS parameters pci=pcie_bus_safe, pci=pcie_bus_perf, etc
  PCI: Document hpiosize= and hpmemsize= resource reservation parameters
  PCI: Use PCI Express Capability accessor
  PCI: Introduce accessor to retrieve PCIe Capabilities Register
  PCI: Put pci_dev in device tree as early as possible
  PCI: Skip attaching driver in device_add()
  PCI: acpiphp: Keep driver loaded even if no slots found
  ...

PCI/PM: Clean up PME state when removing a device

2013-02-13T18:58:02+00:00

Devices are added to pci_pme_list when drivers use pci_enable_wake()
or pci_wake_from_d3(), but they aren't removed from the list unless
the driver explicitly disables wakeup.  Many drivers never disable
wakeup, so their devices remain on the list even after they are
removed, e.g., via hotplug.  A subsequent PME poll will oops when
it tries to touch the device.

This patch disables PME# on a device before removing it, which removes
the device from pci_pme_list.  This is safe even if the device never
had PME# enabled.

This oops can be triggered by unplugging a Thunderbolt ethernet adapter
on a Macbook Pro, as reported by Daniel below.

[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2svG21yiM1wkH4_2pen2n+cr2-Zv7TbH3Gj+8MwevZjDbw@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org

PCI: Make device create/destroy logic symmetric

2013-01-25T21:42:06+00:00

According to device model documentation, the way to create/destroy PCI
devices should be symmetric.  The rule is to either use
  1) device_register()/device_unregister()
or
  2) device_initialize()/device_add()/device_del()/put_device().

So change PCI core logic to follow the rule and get rid of the redundant
pci_dev_get()/pci_dev_put() pair.

Signed-off-by: Jiang Liu 
Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki

PCI: Add pci_stop_and_remove_root_bus()

2012-11-03T22:26:37+00:00

It supports both PCI root bus and PCI bus under PCI bridge.

Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas

PCI: Stop all children first, before removing all children

2012-09-20T23:37:23+00:00

This restores the previous behavior of stopping all child devices before
removing any of them.  The current SR-IOV design, where removing the PF
also drops references on all the VFs, depends on having the VFs continue
to exist after having been stopped.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas

PCI: Leave normal LIST_POISON in deleted list entries

2012-08-22T17:34:38+00:00

list_del() already sets next/prev to LIST_POISON1/LIST_POISON2, so we
don't need to do anything special here to prevent further list accesses.

Tested-by: Yijing Wang 
Signed-off-by: Bjorn Helgaas 
Acked-by: Yinghai Lu