linux-stable.git/drivers/pci, branch v3.8.8

PCI/PM: Disable runtime PM of PCIe ports

2013-04-12T16:52:07+00:00

commit de7d5f729c72638f41d7c17487bccb1c570ff144 upstream.

The runtime PM of PCIe ports turns out to be quite fragile, as in
some cases things work while in some other cases they don't and we
don't seem to have a good way to determine whether or not they are
going to work in advance.

For this reason, avoid enabling runtime PM for PCIe ports by
keeping their runtime PM reference counters always above 0 for the
time being.

When a PCIe port is suspended, it can no longer report events like
hotplug, so hotplug below the port may not work, as in the bug
report below.

[bhelgaas: changelog, stable]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=53811
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

PCI/ACPI: Always resume devices on ACPI wakeup notifications

2013-04-12T16:52:06+00:00

commit 24ad0ef9c8b946ed2abe681e4e44f4a1e643d882 upstream.

It turns out that the _Lxx control methods provided by some BIOSes
clear the PME Status bit of PCI devices they handle, which means that
pci_acpi_wake_dev() cannot really use that bit to check whether or
not the device has signalled wakeup.

One symptom of the problem is, for example, that when an affected PCI
USB controller is runtime-suspended, then plugging in a new USB device
into one of the controller's ports will not wake up the controller,
which should happen.

For this reason, make pci_acpi_wake_dev() always attempt to resume
the device it is called for regardless of the device's PME Status bit
value (that bit still has to be cleared if set at this point,
though).

Reported-by: Sarah Sharp 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas 
Acked-by: Matthew Garrett 
Signed-off-by: Greg Kroah-Hartman

PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGS

2013-02-28T13:38:35+00:00

commit 969daa349f4821a02936af7202b51a9affc7b6da upstream.

PCI_EXP_FLAGS_TYPE is a mask, not an offset.  Fix it.

Previously, pcie_capability_read_word(..., PCI_EXP_FLAGS, ...) would
fail.

[bhelgaas:  tweak changelog]
Signed-off-by: Alex Williamson 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

Merge tag '3.8-pci-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2013-02-15T20:04:08+00:00

Pull PCI fix from Bjorn Helgaas:
 "This is another fix for v3.8.  It fixes an oops that happens when a
  Thunderbolt adapter is unplugged (remove device, poll for PME events
  on no-longer-existing device, oops)."

* tag '3.8-pci-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/PM: Clean up PME state when removing a device

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

Merge tag '3.8-pci-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2013-01-23T00:36:23+00:00

Pull PCI updates from Bjorn Helgaas:
 "The most important is a fix for a pciehp deadlock that occurs when
  unplugging a Thunderbolt adapter.  We also applied the same fix to
  shpchp, removed CONFIG_EXPERIMENTAL dependencies, fixed a
  pcie_aspm=force problem, and fixed a refcount leak.

  Details:

   - Hotplug
      PCI: pciehp: Use per-slot workqueues to avoid deadlock
      PCI: shpchp: Make shpchp_wq non-ordered
      PCI: shpchp: Handle push button event asynchronously
      PCI: shpchp: Use per-slot workqueues to avoid deadlock

   - Power management
      PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported

   - Misc
      PCI/AER: pci_get_domain_bus_and_slot() call missing required pci_dev_put()
      PCI: remove depends on CONFIG_EXPERIMENTAL"

* tag '3.8-pci-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: remove depends on CONFIG_EXPERIMENTAL
  PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported
  PCI: shpchp: Use per-slot workqueues to avoid deadlock
  PCI: shpchp: Handle push button event asynchronously
  PCI: shpchp: Make shpchp_wq non-ordered
  PCI/AER: pci_get_domain_bus_and_slot() call missing required pci_dev_put()
  PCI: pciehp: Use per-slot workqueues to avoid deadlock

PCI: remove depends on CONFIG_EXPERIMENTAL

2013-01-17T23:22:05+00:00

The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

Signed-off-by: Kees Cook 
Signed-off-by: Bjorn Helgaas

PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported

2013-01-14T23:23:42+00:00

Right now using pcie_aspm=force will not enable ASPM if the FADT indicates
ASPM is unsupported.  However, the semantics of force should probably allow
for this, especially as they did before 3c076351c4 ("PCI: Rework ASPM
disable code")

This patch just skips the clearing of any ASPM setup that the firmware has
carried out on this bus if pcie_aspm=force is being used.

Reference: http://bugs.launchpad.net/bugs/962038
Signed-off-by: Colin Ian King 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org

Merge branch 'pci/yijing-hotplug-workqueues' into for-linus

2013-01-14T17:25:13+00:00

* pci/yijing-hotplug-workqueues:
  PCI: shpchp: Use per-slot workqueues to avoid deadlock
  PCI: shpchp: Handle push button event asynchronously
  PCI: shpchp: Make shpchp_wq non-ordered
  PCI: pciehp: Use per-slot workqueues to avoid deadlock

PCI: shpchp: Use per-slot workqueues to avoid deadlock

2013-01-14T17:23:22+00:00

When we have an SHPC-capable bridge with a second SHPC-capable bridge
below it, pushing the upstream bridge's attention button causes a
deadlock.

The deadlock happens because we use the shpchp_wq workqueue to run
shpchp_pushbutton_thread(), which uses shpchp_disable_slot() to remove
devices below the upstream bridge.  When we remove the downstream bridge,
we call shpc_remove(), the shpchp driver's .remove() method.  That calls
flush_workqueue(shpchp_wq), which deadlocks because the
shpchp_pushbutton_thread() work item is still running.

This patch avoids the deadlock by creating a workqueue for every slot
and removing the single shared workqueue.

Here's the call path that leads to the deadlock:

  shpchp_queue_pushbutton_work
    queue_work(shpchp_wq)		# shpchp_pushbutton_thread
    ...

  shpchp_pushbutton_thread
    shpchp_disable_slot
      remove_board
        shpchp_unconfigure_device
          pci_stop_and_remove_bus_device
            ...
              shpc_remove		# shpchp driver .remove method
                hpc_release_ctlr
                  cleanup_slots
                    flush_workqueue(shpchp_wq)

This change is based on code inspection, since we don't have hardware
with this topology.

Based-on-patch-by: Yijing Wang 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org