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  1. 03 4月, 2013 1 次提交
    • B
      Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus" · b8178f13
      由 Bjorn Helgaas 提交于 
      This reverts commit 8c33f51d.

Conflicts:
	drivers/acpi/pci_root.c

This commit broke some pre-1.1 PCIe devices by leaving them with
ASPM enabled.  Previously, we had disabled ASPM on these devices
because many of them don't implement it correctly (per 149e1637).

Requesting _OSC control early means that aspm_disabled may be set
before we scan the PCI bus and configure link ASPM state.  But the
ASPM configuration currently skips the check for pre-PCIe 1.1 devices
when aspm_disabled is set, like this:

    acpi_pci_root_add
      acpi_pci_osc_support
        if (flags != base_flags)
          pcie_no_aspm
            aspm_disabled = 1
      pci_acpi_scan_root
        ...
          pcie_aspm_init_link_state
            pcie_aspm_sanity_check
              if (!aspm_disabled)
                /* check for pre-PCIe 1.1 device */

Therefore, setting aspm_disabled early means that we leave ASPM enabled
on these pre-PCIe 1.1 devices, which is a regression for some devices.

The best fix would be to clean up the ASPM init so we can evaluate
_OSC before scanning the bug (that way boot-time and hot-add discovery
will work the same), but that requires significant rework.

For now, we'll just revert the _OSC change as the lowest-risk fix.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=55211Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
CC: stable@vger.kernel.org	# v3.8+
      b8178f13
  3. 27 3月, 2013 1 次提交
  5. 17 2月, 2013 1 次提交
  7. 30 1月, 2013 1 次提交
  9. 26 1月, 2013 3 次提交
  11. 14 1月, 2013 1 次提交
    • R
      ACPI / PCI: Set root bridge ACPI handle in advance · 6c0cc950
      由 Rafael J. Wysocki 提交于 
      The ACPI handles of PCI root bridges need to be known to
acpi_bind_one(), so that it can create the appropriate
"firmware_node" and "physical_node" files for them, but currently
the way it gets to know those handles is not exactly straightforward
(to put it lightly).

This is how it works, roughly:

  1. acpi_bus_scan() finds the handle of a PCI root bridge,
     creates a struct acpi_device object for it and passes that
     object to acpi_pci_root_add().

  2. acpi_pci_root_add() creates a struct acpi_pci_root object,
     populates its "device" field with its argument's address
     (device->handle is the ACPI handle found in step 1).

  3. The struct acpi_pci_root object created in step 2 is passed
     to pci_acpi_scan_root() and used to get resources that are
     passed to pci_create_root_bus().

  4. pci_create_root_bus() creates a struct pci_host_bridge object
     and passes its "dev" member to device_register().

  5. platform_notify(), which for systems with ACPI is set to
     acpi_platform_notify(), is called.

So far, so good.  Now it starts to be "interesting".

  6. acpi_find_bridge_device() is used to find the ACPI handle of
     the given device (which is the PCI root bridge) and executes
     acpi_pci_find_root_bridge(), among other things, for the
     given device object.

  7. acpi_pci_find_root_bridge() uses the name (sic!) of the given
     device object to extract the segment and bus numbers of the PCI
     root bridge and passes them to acpi_get_pci_rootbridge_handle().

  8. acpi_get_pci_rootbridge_handle() browses the list of ACPI PCI
     root bridges and finds the one that matches the given segment
     and bus numbers.  Its handle is then used to initialize the
     ACPI handle of the PCI root bridge's device object by
     acpi_bind_one().  However, this is *exactly* the ACPI handle we
     started with in step 1.

Needless to say, this is quite embarassing, but it may be avoided
thanks to commit f3fd0c8a (ACPI: Allow ACPI handles of devices to be
initialized in advance), which makes it possible to initialize the
ACPI handle of a device before passing it to device_register().

Accordingly, add a new __weak routine, pcibios_root_bridge_prepare(),
defaulting to an empty implementation that can be replaced by the
interested architecutres (x86 and ia64 at the moment) with functions
that will set the root bridge's ACPI handle before its dev member is
passed to device_register().  Make both x86 and ia64 provide such
implementations of pcibios_root_bridge_prepare() and remove
acpi_pci_find_root_bridge() and acpi_get_pci_rootbridge_handle() that
aren't necessary any more.

Included is a fix for breakage on systems with non-ACPI PCI host
bridges from Bjorn Helgaas.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      6c0cc950
  13. 08 1月, 2013 1 次提交
  15. 03 1月, 2013 3 次提交
    • R
      ACPI / PCI: Move the _PRT setup and cleanup code to pci-acpi.c · 38a9a67a
      由 Rafael J. Wysocki 提交于 
      Move the code related to _PRT setup and removal and to power
resources from acpi_pci_bind() and acpi_pci_unbind() to the .setup()
and .cleanup() callbacks in acpi_pci_bus and remove acpi_pci_bind()
and acpi_pci_unbind() that have no purpose any more.  Accordingly,
remove the code related to device .bind() and .unbind() operations
from the ACPI PCI root bridge driver.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NToshi Kani <toshi.kani@hp.com>
      38a9a67a
    • R
      ACPI / PCI: Fold acpi_pci_root_start() into acpi_pci_root_add() · 47525cda
      由 Rafael J. Wysocki 提交于 
      Move the code from the ACPI PCI root bridge's .start() callback
routine, acpi_pci_root_start(), directly into acpi_pci_root_add()
and drop acpi_pci_root_start().

It is safe to do that, because it is now always guaranteed that
when struct pci_dev objects are created, their companion struct
acpi_device objects are already present, so it is not necessary to
wait for them to be created before calling pci_bus_add_devices().

This change was previously proposed in a different form by
Yinghai Lu.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NToshi Kani <toshi.kani@hp.com>
      47525cda
    • R
      ACPI: Change the ordering of PCI root bridge driver registrarion · 92ef2a25
      由 Rafael J. Wysocki 提交于 
      Instead of running acpi_pci_root_init() from a separate subsys
initcall, call it directly from acpi_scan_init() before scanning the
ACPI namespace for the first time, so that the PCI root bridge
driver's .add() routine, acpi_pci_root_start(), is always run
before binding ACPI drivers or attaching "companion" device objects
to struct acpi_device objects below the root bridge's device node in
the ACPI namespace.

The first, simpler reason for doing this is that it makes the
situation during boot more similar to the situation during hotplug,
in which the ACPI PCI root bridge driver is always present.

The second reason is that acpi_pci_root_init() causes struct pci_dev
objects to be created for all PCI devices below the bridge and
these objects may be necessary for whatever is done with the other
ACPI device nodes in that namespace scope.  For example, devices
created by acpi_create_platform_device() sometimes may need to be
added to the device hierarchy as children of PCI bridges.  For this
purpose, however, the struct pci_dev objects representing those
bridges need to exist before the platform devices in question are
registered.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NToshi Kani <toshi.kani@hp.com>
      92ef2a25
  17. 29 11月, 2012 1 次提交
  19. 08 11月, 2012 2 次提交
  21. 06 11月, 2012 2 次提交
  23. 04 11月, 2012 4 次提交
  25. 25 9月, 2012 6 次提交
  27. 31 7月, 2012 1 次提交
    • R
      ACPI / PCI: Do not try to acquire _OSC control if that is hopeless · 2d9c8677
      由 Rafael J. Wysocki 提交于 
      If acpi_pci_osc_support() fails for the given flags, it doesn't make
sense to call acpi_pci_osc_control_set() down the road for the same
flags, because it will certainly fail too.  Moreover, problem
diagnostics is then harder, because it is not too easy to identify
the reason of the _OSC failure in those cases.

For this reason, check the status returned by acpi_pci_osc_support()
for PCIe support flags and do not attempt to execute
acpi_pci_osc_control_set() for those flags and print a message if
it's "failure".  For compatibility with the existing code, disable
ASPM in that case too.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>
      2d9c8677
  29. 23 6月, 2012 1 次提交
  31. 07 1月, 2012 1 次提交
    • M
      PCI: Rework ASPM disable code · 10f6dc7e
      由 Matthew Garrett 提交于 
      Right now we forcibly clear ASPM state on all devices if the BIOS indicates
that the feature isn't supported. Based on the Microsoft presentation
"PCI Express In Depth for Windows Vista and Beyond", I'm starting to think
that this may be an error. The implication is that unless the platform
grants full control via _OSC, Windows will not touch any PCIe features -
including ASPM. In that case clearing ASPM state would be an error unless
the platform has granted us that control.

This patch reworks the ASPM disabling code such that the actual clearing
of state is triggered by a successful handoff of PCIe control to the OS.
The general ASPM code undergoes some changes in order to ensure that the
ability to clear the bits isn't overridden by ASPM having already been
disabled. Further, this theoretically now allows for situations where
only a subset of PCIe roots hand over control, leaving the others in the
BIOS state.

It's difficult to know for sure that this is the right thing to do -
there's zero public documentation on the interaction between all of these
components. But enough vendors enable ASPM on platforms and then set this
bit that it seems likely that they're expecting the OS to leave them alone.

Measured to save around 5W on an idle Thinkpad X220.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      10f6dc7e
  33. 06 12月, 2011 1 次提交
    • M
      PCI: Rework ASPM disable code · 3c076351
      由 Matthew Garrett 提交于 
      Right now we forcibly clear ASPM state on all devices if the BIOS indicates
that the feature isn't supported. Based on the Microsoft presentation
"PCI Express In Depth for Windows Vista and Beyond", I'm starting to think
that this may be an error. The implication is that unless the platform
grants full control via _OSC, Windows will not touch any PCIe features -
including ASPM. In that case clearing ASPM state would be an error unless
the platform has granted us that control.

This patch reworks the ASPM disabling code such that the actual clearing
of state is triggered by a successful handoff of PCIe control to the OS.
The general ASPM code undergoes some changes in order to ensure that the
ability to clear the bits isn't overridden by ASPM having already been
disabled. Further, this theoretically now allows for situations where
only a subset of PCIe roots hand over control, leaving the others in the
BIOS state.

It's difficult to know for sure that this is the right thing to do -
there's zero public documentation on the interaction between all of these
components. But enough vendors enable ASPM on platforms and then set this
bit that it seems likely that they're expecting the OS to leave them alone.

Measured to save around 5W on an idle Thinkpad X220.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      3c076351
  35. 14 7月, 2011 1 次提交
  37. 11 5月, 2011 1 次提交
  39. 22 3月, 2011 2 次提交
    • N
      PCI: Disable ASPM when _OSC control is not granted for PCIe services · eca67315
      由 Naga Chumbalkar 提交于 
      v3 -> v2: Added text to describe the problem
v2 -> v1: Split this patch from v1
v1	: Part of: http://marc.info/?l=linux-pci&m=130042212003242&w=2

Disable ASPM when no _OSC control for PCIe services is granted
by the BIOS. This is to protect systems with a buggy BIOS that
did not set the ACPI FADT "ASPM Controls" bit even though the
underlying HW can't do ASPM.

To turn "on" ASPM the minimum the BIOS needs to do:
1. Clear the ACPI FADT "ASPM Controls" bit.
2. Support _OSC appropriately

There is no _OSC Control bit for ASPM. However, we expect the BIOS to
support _OSC for a Root Bridge that originates a PCIe hierarchy. If this
is not the case - we are better off not enabling ASPM on that server.

Commit 852972ac (ACPI: Disable ASPM if the
Platform won't provide _OSC control for PCIe) describes the above scenario.
To quote verbatim from there:
[The PCI SIG documentation for the _OSC OS/firmware handshaking interface
states:

"If the _OSC control method is absent from the scope of a host bridge
device, then the operating system must not enable or attempt to use any
features defined in this section for the hierarchy originated by the host
bridge."

The obvious interpretation of this is that the OS should not attempt to use
PCIe hotplug, PME or AER - however, the specification also notes that an
_OSC method is *required* for PCIe hierarchies, and experimental validation
with An Alternative OS indicates that it doesn't use any PCIe functionality
if the _OSC method is missing. That arguably means we shouldn't be using
MSI or extended config space, but right now our problems seem to be limited
to vendors being surprised when ASPM gets enabled on machines when other
OSs refuse to do so. So, for now, let's just disable ASPM if the _OSC
method doesn't exist or refuses to hand over PCIe capability control.]
Signed-off-by: NNaga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      eca67315
    • R
      PCI/ACPI: Report ASPM support to BIOS if not disabled from command line · 8b8bae90
      由 Rafael J. Wysocki 提交于 
      We need to distinguish the situation in which ASPM support is
disabled from the command line or through .config from the situation
in which it is disabled, because the hardware or BIOS can't handle
it.  In the former case we should not report ASPM support to the BIOS
through ACPI _OSC, but in the latter case we should do that.

Introduce pcie_aspm_support_enabled() that can be used by
acpi_pci_root_add() to determine whether or not it should report ASPM
support to the BIOS through _OSC.

Cc: stable@kernel.org
References: https://bugzilla.kernel.org/show_bug.cgi?id=29722
References: https://bugzilla.kernel.org/show_bug.cgi?id=20232Reported-and-tested-by: NOrtwin Glück <odi@odi.ch>
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      8b8bae90
  41. 17 1月, 2011 1 次提交
  43. 15 1月, 2011 1 次提交
  45. 16 10月, 2010 1 次提交
  47. 25 8月, 2010 2 次提交
    • R
      PCI: PCIe: Ask BIOS for control of all native services at once · 28eb5f27
      由 Rafael J. Wysocki 提交于 
      After commit 852972ac (ACPI: Disable
ASPM if the platform won't provide _OSC control for PCIe) control of
the PCIe Capability Structure is unconditionally requested by
acpi_pci_root_add(), which in principle may cause problems to
happen in two ways.  First, the BIOS may refuse to give control of
the PCIe Capability Structure if it is not asked for any of the
_OSC features depending on it at the same time.  Second, the BIOS may
assume that control of the _OSC features depending on the PCIe
Capability Structure will be requested in the future and may behave
incorrectly if that doesn't happen.  For this reason, control of
the PCIe Capability Structure should always be requested along with
control of any other _OSC features that may depend on it (ie. PCIe
native PME, PCIe native hot-plug, PCIe AER).

Rework the PCIe port driver so that (1) it checks which native PCIe
port services can be enabled, according to the BIOS, and (2) it
requests control of all these services simultaneously.  In
particular, this causes pcie_portdrv_probe() to fail if the BIOS
refuses to grant control of the PCIe Capability Structure, which
means that no native PCIe port services can be enabled for the PCIe
Root Complex the given port belongs to.  If that happens, ASPM is
disabled to avoid problems with mishandling it by the part of the
PCIe hierarchy for which control of the PCIe Capability Structure
has not been received.

Make it possible to override this behavior using 'pcie_ports=native'
(use the PCIe native services regardless of the BIOS response to the
control request), or 'pcie_ports=compat' (do not use the PCIe native
services at all).

Accordingly, rework the existing PCIe port service drivers so that
they don't request control of the services directly.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      28eb5f27
    • R
      ACPI/PCI: Negotiate _OSC control bits before requesting them · 75fb60f2
      由 Rafael J. Wysocki 提交于 
      It is possible that the BIOS will not grant control of all _OSC
features requested via acpi_pci_osc_control_set(), so it is
recommended to negotiate the final set of _OSC features with the
query flag set before calling _OSC to request control of these
features.

To implement it, rework acpi_pci_osc_control_set() so that the caller
can specify the mask of _OSC control bits to negotiate and the mask
of _OSC control bits that are absolutely necessary to it.  Then,
acpi_pci_osc_control_set() will run _OSC queries in a loop until
the mask of _OSC control bits returned by the BIOS is equal to the
mask passed to it.  Also, before running the _OSC request
acpi_pci_osc_control_set() will check if the caller's required
control bits are present in the final mask.

Using this mechanism we will be able to avoid situations in which the
BIOS doesn't grant control of certain _OSC features, because they
depend on some other _OSC features that have not been requested.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      75fb60f2