<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/acpi/scan.c, branch v3.9.2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'pm+acpi-fixes-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2013-02-26T05:25:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-02-26T05:25:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c41b3810c09e60664433548c5218cc6ece6a8903'/>
<id>c41b3810c09e60664433548c5218cc6ece6a8903</id>
<content type='text'>
Pull ACPI and power management fixes from Rafael Wysocki:

 - Fixes for blackfin and microblaze build problems introduced by the
   removal of global pm_idle.  From Lars-Peter Clausen.

 - OPP core build fix from Shawn Guo.

 - Error condition check fix for the new imx6q-cpufreq driver from Wei
   Yongjun.

 - Fix for an AER driver crash related to the lack of APEI
   initialization for acpi=off.  From Rafael J Wysocki.

 - Fix for a USB breakage on Thinkpad T430 related to ACPI power
   resources and PCI wakeup from Rafael J.  Wysocki.

* tag 'pm+acpi-fixes-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PM: Take unusual configurations of power resources into account
  imx6q-cpufreq: fix return value check in imx6q_cpufreq_probe()
  PM / OPP: fix condition for empty of_init_opp_table()
  ACPI / APEI: Fix crash in apei_hest_parse() for acpi=off
  microblaze idle: Fix compile error
  blackfin idle: Fix compile error
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ACPI and power management fixes from Rafael Wysocki:

 - Fixes for blackfin and microblaze build problems introduced by the
   removal of global pm_idle.  From Lars-Peter Clausen.

 - OPP core build fix from Shawn Guo.

 - Error condition check fix for the new imx6q-cpufreq driver from Wei
   Yongjun.

 - Fix for an AER driver crash related to the lack of APEI
   initialization for acpi=off.  From Rafael J Wysocki.

 - Fix for a USB breakage on Thinkpad T430 related to ACPI power
   resources and PCI wakeup from Rafael J.  Wysocki.

* tag 'pm+acpi-fixes-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PM: Take unusual configurations of power resources into account
  imx6q-cpufreq: fix return value check in imx6q_cpufreq_probe()
  PM / OPP: fix condition for empty of_init_opp_table()
  ACPI / APEI: Fix crash in apei_hest_parse() for acpi=off
  microblaze idle: Fix compile error
  blackfin idle: Fix compile error
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci</title>
<updated>2013-02-26T05:18:18+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-02-26T05:18:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=556f12f602ac0a18a82ca83e9f8e8547688fc633'/>
<id>556f12f602ac0a18a82ca83e9f8e8547688fc633</id>
<content type='text'>
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
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'acpi-pm' into fixes</title>
<updated>2013-02-23T22:15:43+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-02-23T22:15:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4383822020c54c21eb2eb939a3233b44a51e8ca0'/>
<id>4383822020c54c21eb2eb939a3233b44a51e8ca0</id>
<content type='text'>
* acpi-pm:
  ACPI / PM: Take unusual configurations of power resources into account
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* acpi-pm:
  ACPI / PM: Take unusual configurations of power resources into account
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PM: Take unusual configurations of power resources into account</title>
<updated>2013-02-23T22:15:21+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-02-23T22:15:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b5d667eb392ed901fc7ae76869c7a130559e193c'/>
<id>b5d667eb392ed901fc7ae76869c7a130559e193c</id>
<content type='text'>
Commit d2e5f0c (ACPI / PCI: Rework the setup and cleanup of device
wakeup) moved the initial disabling of system wakeup for PCI devices
into a place where it can actually work and that exposed a hidden old
issue with crap^Wunusual system designs where the same power
resources are used for both wakeup power and device power control at
run time.

Namely, say there is one power resource such that the ACPI power
state D0 of a PCI device depends on that power resource (i.e. the
device is in D0 when that power resource is "on") and it is used
as a wakeup power resource for the same device.  Then, calling
acpi_pci_sleep_wake(pci_dev, false) for the device in question will
cause the reference counter of that power resource to drop to 0,
which in turn will cause it to be turned off.  As a result, the
device will go into D3cold at that point, although it should have
stayed in D0.

As it turns out, that happens to USB controllers on some laptops
and USB becomes unusable on those machines as a result, which is
a major regression from v3.8.

To fix this problem, (1) increment the reference counters of wakup
power resources during their initialization if they are "on"
initially, (2) prevent acpi_disable_wakeup_device_power() from
decrementing the reference counters of wakeup power resources that
were not enabled for wakeup power previously, and (3) prevent
acpi_enable_wakeup_device_power() from incrementing the reference
counters of wakeup power resources that already are enabled for
wakeup power.

In addition to that, if it is impossible to determine the initial
states of wakeup power resources, avoid enabling wakeup for devices
whose wakeup power depends on those power resources.

Reported-by: Dave Jones &lt;davej@redhat.com&gt;
Reported-by: Fabio Baltieri &lt;fabio.baltieri@linaro.org&gt;
Tested-by: Fabio Baltieri &lt;fabio.baltieri@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit d2e5f0c (ACPI / PCI: Rework the setup and cleanup of device
wakeup) moved the initial disabling of system wakeup for PCI devices
into a place where it can actually work and that exposed a hidden old
issue with crap^Wunusual system designs where the same power
resources are used for both wakeup power and device power control at
run time.

Namely, say there is one power resource such that the ACPI power
state D0 of a PCI device depends on that power resource (i.e. the
device is in D0 when that power resource is "on") and it is used
as a wakeup power resource for the same device.  Then, calling
acpi_pci_sleep_wake(pci_dev, false) for the device in question will
cause the reference counter of that power resource to drop to 0,
which in turn will cause it to be turned off.  As a result, the
device will go into D3cold at that point, although it should have
stayed in D0.

As it turns out, that happens to USB controllers on some laptops
and USB becomes unusable on those machines as a result, which is
a major regression from v3.8.

To fix this problem, (1) increment the reference counters of wakup
power resources during their initialization if they are "on"
initially, (2) prevent acpi_disable_wakeup_device_power() from
decrementing the reference counters of wakeup power resources that
were not enabled for wakeup power previously, and (3) prevent
acpi_enable_wakeup_device_power() from incrementing the reference
counters of wakeup power resources that already are enabled for
wakeup power.

In addition to that, if it is impossible to determine the initial
states of wakeup power resources, avoid enabling wakeup for devices
whose wakeup power depends on those power resources.

Reported-by: Dave Jones &lt;davej@redhat.com&gt;
Reported-by: Fabio Baltieri &lt;fabio.baltieri@linaro.org&gt;
Tested-by: Fabio Baltieri &lt;fabio.baltieri@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'pci/jiang-pci_slot-kconfig' into next</title>
<updated>2013-02-16T00:44:01+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2013-02-16T00:44:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ad06bff31fbf0aba4e5faae936e12292a7972b05'/>
<id>ad06bff31fbf0aba4e5faae936e12292a7972b05</id>
<content type='text'>
* pci/jiang-pci_slot-kconfig:
  ACPI / PCI: Make pci_slot built-in only, not a module
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pci/jiang-pci_slot-kconfig:
  ACPI / PCI: Make pci_slot built-in only, not a module
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PCI: Make pci_slot built-in only, not a module</title>
<updated>2013-02-15T18:35:05+00:00</updated>
<author>
<name>Jiang Liu</name>
<email>liuj97@gmail.com</email>
</author>
<published>2013-01-18T16:07:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ab1a2e038ff2336502e95ec6492c0364a9fc70d0'/>
<id>ab1a2e038ff2336502e95ec6492c0364a9fc70d0</id>
<content type='text'>
As discussed in thread at https://patchwork.kernel.org/patch/1946851/,
there's no value in supporting CONFIG_ACPI_PCI_SLOT=m any more.
So change Kconfig and code to only support building pci_slot as
built-in driver.

Signed-off-by: Jiang Liu &lt;jiang.liu@huawei.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As discussed in thread at https://patchwork.kernel.org/patch/1946851/,
there's no value in supporting CONFIG_ACPI_PCI_SLOT=m any more.
So change Kconfig and code to only support building pci_slot as
built-in driver.

Signed-off-by: Jiang Liu &lt;jiang.liu@huawei.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'acpi-cleanup'</title>
<updated>2013-02-15T12:58:30+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-02-15T12:58:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e8f71df723339b6d3861886f58c245812d1994f8'/>
<id>e8f71df723339b6d3861886f58c245812d1994f8</id>
<content type='text'>
* acpi-cleanup: (21 commits)
  ACPI / hotplug: Fix concurrency issues and memory leaks
  ACPI: Remove the use of CONFIG_ACPI_CONTAINER_MODULE
  ACPI / scan: Full transition to D3cold in acpi_device_unregister()
  ACPI / scan: Make acpi_bus_hot_remove_device() acquire the scan lock
  ACPI: Drop the container.h header file
  ACPI / Documentation: refer to correct file for acpi_platform_device_ids[] table
  ACPI / scan: Make container driver use struct acpi_scan_handler
  ACPI / scan: Remove useless #ifndef from acpi_eject_store()
  ACPI: Unbind ACPI drv when probe failed
  ACPI: sysfs eject support for ACPI scan handlers
  ACPI / scan: Follow priorities of IDs when matching scan handlers
  ACPI / PCI: pci_slot: replace printk(KERN_xxx) with pr_xxx()
  ACPI / dock: Fix acpi_bus_get_device() check in drivers/acpi/dock.c
  ACPI / scan: Clean up acpi_bus_get_parent()
  ACPI / platform: Use struct acpi_scan_handler for creating devices
  ACPI / PCI: Make PCI IRQ link driver use struct acpi_scan_handler
  ACPI / PCI: Make PCI root driver use struct acpi_scan_handler
  ACPI / scan: Introduce struct acpi_scan_handler
  ACPI / scan: Make scanning of fixed devices follow the general scheme
  ACPI: Drop device start operation that is not used
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* acpi-cleanup: (21 commits)
  ACPI / hotplug: Fix concurrency issues and memory leaks
  ACPI: Remove the use of CONFIG_ACPI_CONTAINER_MODULE
  ACPI / scan: Full transition to D3cold in acpi_device_unregister()
  ACPI / scan: Make acpi_bus_hot_remove_device() acquire the scan lock
  ACPI: Drop the container.h header file
  ACPI / Documentation: refer to correct file for acpi_platform_device_ids[] table
  ACPI / scan: Make container driver use struct acpi_scan_handler
  ACPI / scan: Remove useless #ifndef from acpi_eject_store()
  ACPI: Unbind ACPI drv when probe failed
  ACPI: sysfs eject support for ACPI scan handlers
  ACPI / scan: Follow priorities of IDs when matching scan handlers
  ACPI / PCI: pci_slot: replace printk(KERN_xxx) with pr_xxx()
  ACPI / dock: Fix acpi_bus_get_device() check in drivers/acpi/dock.c
  ACPI / scan: Clean up acpi_bus_get_parent()
  ACPI / platform: Use struct acpi_scan_handler for creating devices
  ACPI / PCI: Make PCI IRQ link driver use struct acpi_scan_handler
  ACPI / PCI: Make PCI root driver use struct acpi_scan_handler
  ACPI / scan: Introduce struct acpi_scan_handler
  ACPI / scan: Make scanning of fixed devices follow the general scheme
  ACPI: Drop device start operation that is not used
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / hotplug: Fix concurrency issues and memory leaks</title>
<updated>2013-02-13T13:36:47+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-02-13T13:36:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3757b94802fb65d8f696597a74053cf21738da0b'/>
<id>3757b94802fb65d8f696597a74053cf21738da0b</id>
<content type='text'>
This changeset is aimed at fixing a few different but related
problems in the ACPI hotplug infrastructure.

First of all, since notify handlers may be run in parallel with
acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device()
and some of them are installed for ACPI handles that have no struct
acpi_device objects attached (i.e. before those objects are created),
those notify handlers have to take acpi_scan_lock to prevent races
from taking place (e.g. a struct acpi_device is found to be present
for the given ACPI handle, but right after that it is removed by
acpi_bus_trim() running in parallel to the given notify handler).
Moreover, since some of them call acpi_bus_scan() and
acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock
should be acquired by the callers of these two funtions rather by
these functions themselves.

For these reasons, make all notify handlers that can handle device
addition and eject events take acpi_scan_lock and remove the
acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim().
Accordingly, update all of their users to make sure that they
are always called under acpi_scan_lock.

Furthermore, since eject operations are carried out asynchronously
with respect to the notify events that trigger them, with the help
of acpi_bus_hot_remove_device(), even if notify handlers take the
ACPI scan lock, it still is possible that, for example,
acpi_bus_trim() will run between acpi_bus_hot_remove_device() and
the notify handler that scheduled its execution and that
acpi_bus_trim() will remove the device node passed to
acpi_bus_hot_remove_device() for ejection.  In that case, the struct
acpi_device object obtained by acpi_bus_hot_remove_device() will be
invalid and not-so-funny things will ensue.  To protect agaist that,
make the users of acpi_bus_hot_remove_device() run get_device() on
ACPI device node objects that are about to be passed to it and make
acpi_bus_hot_remove_device() run put_device() on them and check if
their ACPI handles are not NULL (make acpi_device_unregister() clear
the device nodes' ACPI handles for that check to work).

Finally, observe that acpi_os_hotplug_execute() actually can fail,
in which case its caller ought to free memory allocated for the
context object to prevent leaks from happening.  It also needs to
run put_device() on the device node that it ran get_device() on
previously in that case.  Modify the code accordingly.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This changeset is aimed at fixing a few different but related
problems in the ACPI hotplug infrastructure.

First of all, since notify handlers may be run in parallel with
acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device()
and some of them are installed for ACPI handles that have no struct
acpi_device objects attached (i.e. before those objects are created),
those notify handlers have to take acpi_scan_lock to prevent races
from taking place (e.g. a struct acpi_device is found to be present
for the given ACPI handle, but right after that it is removed by
acpi_bus_trim() running in parallel to the given notify handler).
Moreover, since some of them call acpi_bus_scan() and
acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock
should be acquired by the callers of these two funtions rather by
these functions themselves.

For these reasons, make all notify handlers that can handle device
addition and eject events take acpi_scan_lock and remove the
acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim().
Accordingly, update all of their users to make sure that they
are always called under acpi_scan_lock.

Furthermore, since eject operations are carried out asynchronously
with respect to the notify events that trigger them, with the help
of acpi_bus_hot_remove_device(), even if notify handlers take the
ACPI scan lock, it still is possible that, for example,
acpi_bus_trim() will run between acpi_bus_hot_remove_device() and
the notify handler that scheduled its execution and that
acpi_bus_trim() will remove the device node passed to
acpi_bus_hot_remove_device() for ejection.  In that case, the struct
acpi_device object obtained by acpi_bus_hot_remove_device() will be
invalid and not-so-funny things will ensue.  To protect agaist that,
make the users of acpi_bus_hot_remove_device() run get_device() on
ACPI device node objects that are about to be passed to it and make
acpi_bus_hot_remove_device() run put_device() on them and check if
their ACPI handles are not NULL (make acpi_device_unregister() clear
the device nodes' ACPI handles for that check to work).

Finally, observe that acpi_os_hotplug_execute() actually can fail,
in which case its caller ought to free memory allocated for the
context object to prevent leaks from happening.  It also needs to
run put_device() on the device node that it ran get_device() on
previously in that case.  Modify the code accordingly.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / scan: Full transition to D3cold in acpi_device_unregister()</title>
<updated>2013-02-13T12:46:38+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-02-09T14:29:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0aa120a0138398d6597350f4c1dcb46d14be1a0b'/>
<id>0aa120a0138398d6597350f4c1dcb46d14be1a0b</id>
<content type='text'>
In order to drop reference counts of all power resources used by an
ACPI device node being removed, acpi_device_unregister() calls
acpi_power_transition(device, ACPI_STATE_D3_COLD), which effectively
transitions the device node into D3cold if it uses any power
resources.  However, for some device nodes it may not be appropriate
to remove power from them entirely before putting them into D3hot
before.  On the other hand, executing _PS3 for devices that don't
use power resources before removing them shouldn't really hurt.
In fact, that is done by acpi_bus_hot_remove_device(), but this is
not the right place to do it, because the bus trimming may have
caused power to be removed from the device node in question already
before.

For these reasons, make acpi_device_unregister() carry out full
power-off transition for all device nodes supporting that and remove
the direct evaluation of _PS3 from acpi_bus_hot_remove_device().

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In order to drop reference counts of all power resources used by an
ACPI device node being removed, acpi_device_unregister() calls
acpi_power_transition(device, ACPI_STATE_D3_COLD), which effectively
transitions the device node into D3cold if it uses any power
resources.  However, for some device nodes it may not be appropriate
to remove power from them entirely before putting them into D3hot
before.  On the other hand, executing _PS3 for devices that don't
use power resources before removing them shouldn't really hurt.
In fact, that is done by acpi_bus_hot_remove_device(), but this is
not the right place to do it, because the bus trimming may have
caused power to be removed from the device node in question already
before.

For these reasons, make acpi_device_unregister() carry out full
power-off transition for all device nodes supporting that and remove
the direct evaluation of _PS3 from acpi_bus_hot_remove_device().

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / scan: Make acpi_bus_hot_remove_device() acquire the scan lock</title>
<updated>2013-02-13T12:46:31+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-02-09T14:29:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f058cdf4cf3e5181172455f90fc73f2127b6ddf8'/>
<id>f058cdf4cf3e5181172455f90fc73f2127b6ddf8</id>
<content type='text'>
The ACPI scan lock has been introduced to prevent acpi_bus_scan()
and acpi_bus_trim() from running in parallel with each other for
overlapping ACPI namespace scopes.  However, it is not sufficient
to do that, because if acpi_bus_scan() is run (for an overlapping
namespace scope) right after the acpi_bus_trim() in
acpi_bus_hot_remove_device(), the subsequent eject will remove
devices without removing the corresponding struct acpi_device
objects (and possibly companion "physical" device objects).
Therefore acpi_bus_hot_remove_device() has to acquire the scan
lock before carrying out the bus trimming and hold it through
the evaluation of _EJ0, so make that happen.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Toshi Kani &lt;toshi.kani@hp.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ACPI scan lock has been introduced to prevent acpi_bus_scan()
and acpi_bus_trim() from running in parallel with each other for
overlapping ACPI namespace scopes.  However, it is not sufficient
to do that, because if acpi_bus_scan() is run (for an overlapping
namespace scope) right after the acpi_bus_trim() in
acpi_bus_hot_remove_device(), the subsequent eject will remove
devices without removing the corresponding struct acpi_device
objects (and possibly companion "physical" device objects).
Therefore acpi_bus_hot_remove_device() has to acquire the scan
lock before carrying out the bus trimming and hold it through
the evaluation of _EJ0, so make that happen.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Toshi Kani &lt;toshi.kani@hp.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
