linux-toradex.git/drivers/pci/pci-driver.c, branch v3.6

PCI/PM: Keep parent bridge active when probing device

2012-08-21T23:32:07+00:00

This patch fixes the following bug:

http://marc.info/?l=linux-pci&m=134329923124234&w=2

The root cause of the bug is as follow.

If a device is not bound with the corresponding driver, the device
runtime PM will be disabled and the device will be put into suspended
state.  So that, the bridge/PCIe port connected to it may be put into
suspended and low power state.  When do probing for the device later,
because the bridge/PCIe port connected to it is in low power state,
the IO access to device may fail.

To solve the issue, the bridge/PCIe port connected to the device is
put into active state before probing.

Reported-by: Bjorn Mork 
Signed-off-by: Huang Ying 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Rafael J. Wysocki

PCI: EHCI: Fix crash during hibernation on ASUS computers

2012-08-15T17:51:19+00:00

Commit dbf0e4c (PCI: EHCI: fix crash during suspend on ASUS
computers) added a workaround for an ASUS suspend issue related to
USB EHCI and a bug in a number of ASUS BIOSes that attempt to shut
down the EHCI controller during system suspend if its PCI command
register doesn't contain 0 at that time.

It turns out that the same workaround is necessary in the analogous
hibernation code path, so add it.

References: https://bugzilla.kernel.org/show_bug.cgi?id=45811
Reported-and-tested-by: Oleksij Rempel 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas 
Cc: stable@vger.kernel.org

Merge tag 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2012-07-24T23:17:07+00:00

Pull PCI changes from Bjorn Helgaas:
 "Host bridge hotplug:
    - Add MMCONFIG support for hot-added host bridges (Jiang Liu)
  Device hotplug:
    - Move fixups from __init to __devinit (Sebastian Andrzej Siewior)
    - Call FINAL fixups for hot-added devices, too (Myron Stowe)
    - Factor out generic code for P2P bridge hot-add (Yinghai Lu)
    - Remove all functions in a slot, not just those with _EJx (Amos
      Kong)
  Dynamic resource management:
    - Track bus number allocation (struct resource tree per domain)
      (Yinghai Lu)
    - Make P2P bridge 1K I/O windows work with resource reassignment
      (Bjorn Helgaas, Yinghai Lu)
    - Disable decoding while updating 64-bit BARs (Bjorn Helgaas)
  Power management:
    - Add PCIe runtime D3cold support (Huang Ying)
  Virtualization:
    - Add VFIO infrastructure (ACS, DMA source ID quirks) (Alex
      Williamson)
    - Add quirks for devices with broken INTx masking (Jan Kiszka)
  Miscellaneous:
    - Fix some PCI Express capability version issues (Myron Stowe)
    - Factor out some arch code with a weak, generic, pcibios_setup()
      (Myron Stowe)"

* tag 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (122 commits)
  PCI: hotplug: ensure a consistent return value in error case
  PCI: fix undefined reference to 'pci_fixup_final_inited'
  PCI: build resource code for M68K architecture
  PCI: pciehp: remove unused pciehp_get_max_lnk_width(), pciehp_get_cur_lnk_width()
  PCI: reorder __pci_assign_resource() (no change)
  PCI: fix truncation of resource size to 32 bits
  PCI: acpiphp: merge acpiphp_debug and debug
  PCI: acpiphp: remove unused res_lock
  sparc/PCI: replace pci_cfg_fake_ranges() with pci_read_bridge_bases()
  PCI: call final fixups hot-added devices
  PCI: move final fixups from __init to __devinit
  x86/PCI: move final fixups from __init to __devinit
  MIPS/PCI: move final fixups from __init to __devinit
  PCI: support sizing P2P bridge I/O windows with 1K granularity
  PCI: reimplement P2P bridge 1K I/O windows (Intel P64H2)
  PCI: disable MEM decoding while updating 64-bit MEM BARs
  PCI: leave MEM and IO decoding disabled during 64-bit BAR sizing, too
  PCI: never discard enable/suspend/resume_early/resume fixups
  PCI: release temporary reference in __nv_msi_ht_cap_quirk()
  PCI: restructure 'pci_do_fixups()'
  ...

PCI: EHCI: fix crash during suspend on ASUS computers

2012-07-10T16:52:05+00:00

Quite a few ASUS computers experience a nasty problem, related to the
EHCI controllers, when going into system suspend.  It was observed
that the problem didn't occur if the controllers were not put into the
D3 power state before starting the suspend, and commit
151b61284776be2d6f02d48c23c3625678960b97 (USB: EHCI: fix crash during
suspend on ASUS computers) was created to do this.

It turned out this approach messed up other computers that didn't have
the problem -- it prevented USB wakeup from working.  Consequently
commit c2fb8a3fa25513de8fedb38509b1f15a5bbee47b (USB: add
NO_D3_DURING_SLEEP flag and revert 151b61284776be2) was merged; it
reverted the earlier commit and added a whitelist of known good board
names.

Now we know the actual cause of the problem.  Thanks to AceLan Kao for
tracking it down.

According to him, an engineer at ASUS explained that some of their
BIOSes contain a bug that was added in an attempt to work around a
problem in early versions of Windows.  When the computer goes into S3
suspend, the BIOS tries to verify that the EHCI controllers were first
quiesced by the OS.  Nothing's wrong with this, but the BIOS does it
by checking that the PCI COMMAND registers contain 0 without checking
the controllers' power state.  If the register isn't 0, the BIOS
assumes the controller needs to be quiesced and tries to do so.  This
involves making various MMIO accesses to the controller, which don't
work very well if the controller is already in D3.  The end result is
a system hang or memory corruption.

Since the value in the PCI COMMAND register doesn't matter once the
controller has been suspended, and since the value will be restored
anyway when the controller is resumed, we can work around the BIOS bug
simply by setting the register to 0 during system suspend.  This patch
(as1590) does so and also reverts the second commit mentioned above,
which is now unnecessary.

In theory we could do this for every PCI device.  However to avoid
introducing new problems, the patch restricts itself to EHCI host
controllers.

Finally the affected systems can suspend with USB wakeup working
properly.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=37632
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42728
Based-on-patch-by: AceLan Kao 
Signed-off-by: Alan Stern 
Tested-by: Dâniel Fraga 
Tested-by: Javier Marcet 
Tested-by: Andrey Rahmatullin 
Tested-by: Oleksij Rempel 
Tested-by: Pavel Pisa 
Cc: stable 
Acked-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PCI / PM: restore the original behavior of pci_set_power_state()

2012-07-05T21:20:00+00:00

Commit cc2893b6 (PCI: Ensure we re-enable devices on resume)
addressed the problem with USB not being powered after resume on
recent Lenovo machines, but it did that in a suboptimal way.
Namely, it should have changed the relevant code paths only,
which are pci_pm_resume_noirq() and pci_pm_restore_noirq() supposed
to restore the device's power and standard configuration registers
after system resume from suspend or hibernation.  Instead, however,
it modified pci_set_power_state() which is executed in several
other situations too.  That resulted in some undesirable effects,
like attempting to change a device's power state in the same way
multiple times in a row (up to as many as 4 times in a row in the
snd_hda_intel driver).

Fix the bug addressed by commit cc2893b6 in an alternative way,
by forcibly powering up all devices in pci_pm_default_resume_early(),
which is called by pci_pm_resume_noirq() and pci_pm_restore_noirq()
to restore the device's power and standard configuration registers,
and modifying pci_pm_runtime_resume() to avoid the forcible power-up
if not necessary.  Then, revert the changes made by commit cc2893b6
to make the confusion introduced by it go away.

Acked-by: Matthew Garrett 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas

PCI/PM: add PCIe runtime D3cold support

2012-06-23T16:50:59+00:00

This patch adds runtime D3cold support and corresponding ACPI platform
support.  This patch only enables runtime D3cold support; it does not
enable D3cold support during system suspend/hibernate.

D3cold is the deepest power saving state for a PCIe device, where its main
power is removed.  While it is in D3cold, you can't access the device at
all, not even its configuration space (which is still accessible in D3hot).
Therefore the PCI PM registers can not be used to transition into/out of
the D3cold state; that must be done by platform logic such as ACPI _PR3.

To support wakeup from D3cold, a system may provide auxiliary power, which
allows a device to request wakeup using a Beacon or the sideband WAKE#
signal.  WAKE# is usually connected to platform logic such as ACPI GPE.
This is quite different from other power saving states, where devices
request wakeup via a PME message on the PCIe link.

Some devices, such as those in plug-in slots, have no direct platform
logic.  For example, there is usually no ACPI _PR3 for them.  D3cold
support for these devices can be done via the PCIe Downstream Port leading
to the device.  When the PCIe port is powered on/off, the device is powered
on/off too.  Wakeup events from the device will be notified to the
corresponding PCIe port.

For more information about PCIe D3cold and corresponding ACPI support,
please refer to:

- PCI Express Base Specification Revision 2.0
- Advanced Configuration and Power Interface Specification Revision 5.0

[bhelgaas: changelog]
Reviewed-by: Rafael J. Wysocki 
Originally-by: Zheng Yan 
Signed-off-by: Huang Ying 
Signed-off-by: Bjorn Helgaas

PCI: disable Bus Master on PCI device shutdown

2012-05-04T17:07:18+00:00

Disable Bus Master bit on the device in pci_device_shutdown() to ensure PCI
devices do not continue to DMA data after shutdown.  This can cause memory
corruption in case of a kexec where the current kernel shuts down and
transfers control to a new kernel while a PCI device continues to DMA to
memory that does not belong to it any more in the new kernel.

I have tested this code on two laptops, two workstations and a 16-socket
server.  kexec worked correctly on all of them.

Signed-off-by: Khalid Aziz 
Signed-off-by: Bjorn Helgaas

Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci

2012-03-23T21:02:12+00:00

Pull PCI changes (including maintainer change) from Jesse Barnes:
 "This pull has some good cleanups from Bjorn and Yinghai, as well as
  some more code from Yinghai to better handle resource re-allocation
  when enabled.

  There's also a new initcall_debug feature from Arjan which will print
  out quirk timing information to help identify slow quirks for fixing
  or refinement (Yinghai sent in a few patches to do just that once the
  new debug code landed).

  Beyond that, I'm handing off PCI maintainership to Bjorn Helgaas.
  He's been a core PCI and Linux contributor for some time now, and has
  kindly volunteered to take over.  I just don't feel I have the time
  for PCI review and work that it deserves lately (I've taken on some
  other projects), and haven't been as responsive lately as I'd like, so
  I approached Bjorn asking if he'd like to manage things.  He's going
  to give it a try, and I'm confident he'll do at least as well as I
  have in keeping the tree managed, patches flowing, and keeping things
  stable."

Fix up some fairly trivial conflicts due to other cleanups (mips device
resource fixup cleanups clashing with list handling cleanup, ppc iseries
removal clashing with pci_probe_only cleanup etc)

* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (112 commits)
  PCI: Bjorn gets PCI hotplug too
  PCI: hand PCI maintenance over to Bjorn Helgaas
  unicore32/PCI: move  include to asm/pci.h
  sparc/PCI: convert devtree and arch-probed bus addresses to resource
  powerpc/PCI: allow reallocation on PA Semi
  powerpc/PCI: convert devtree bus addresses to resource
  powerpc/PCI: compute I/O space bus-to-resource offset consistently
  arm/PCI: don't export pci_flags
  PCI: fix bridge I/O window bus-to-resource conversion
  x86/PCI: add spinlock held check to 'pcibios_fwaddrmap_lookup()'
  PCI / PCIe: Introduce command line option to disable ARI
  PCI: make acpihp use __pci_remove_bus_device instead
  PCI: export __pci_remove_bus_device
  PCI: Rename pci_remove_behind_bridge to pci_stop_and_remove_behind_bridge
  PCI: Rename pci_remove_bus_device to pci_stop_and_remove_bus_device
  PCI: print out PCI device info along with duration
  PCI: Move "pci reassigndev resource alignment" out of quirks.c
  PCI: Use class for quirk for usb host controller fixup
  PCI: Use class for quirk for ti816x class fixup
  PCI: Use class for quirk for intel e100 interrupt fixup
  ...

PCI / PM: Disable wakeup during shutdown for devices not enabled to wake up

2012-02-17T17:22:04+00:00

If a PCI device is enabled to generate wakeup signals (PME) when put
into a low-power state by runtime PM, it will be still enabled to
generate those signals after the system shutdown, unless its driver's
.shutdown() callback takes care of the wakeup signals generation
setting.  Moreover, there are devices that are not enabled to wake
up the system and that are configured by runtime PM to generate
wakeup signals so that (runtime) remote wakeup works with them.
Those devices should be reconfigured during system shutdown so that
they don't generate wakeup signals, but at least some drivers don't
do that.  However, that very well may be done by the PCI core so
that drivers don't have to worry about it.  For this reason, modify
pci_device_shutdown() to disable the generation of wakeup events for
devices not supposed to wake up the system.

References: https://bugzilla.kernel.org/show_bug.cgi?id=37952
Reported-and-tested-by: Kamil Iskra 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jesse Barnes

USB/PCI/PCMCIA: Clean up new_id and remove_id sysfs attribute routines

2012-01-27T01:04:39+00:00

This patch (as1514) cleans up some places where new_id and remove_id
sysfs attributes are created and deleted.  Handling both attributes in
a single routine rather than a pair of routines makes the code
smaller.  It also prevents certain kinds of errors, like one we
currently have in the USB subsystem: The removeid attribute is often
created even when newid isn't (because the driver's no_dynamid_id flag
is set).

In the case of the PCMCIA subsystem, the newid attribute is created
but never explicitly deleted.  The patch adds a deletion routine.

Signed-off-by: Alan Stern 
Acked-by: Jesse Barnes 
Acked-by: Dominik Brodowski 
Signed-off-by: Greg Kroah-Hartman