<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/acpi, branch v3.10.94</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>ACPICA: Tables: Fix an issue that FACS initialization is performed twice</title>
<updated>2015-08-03T16:29:46+00:00</updated>
<author>
<name>Lv Zheng</name>
<email>lv.zheng@intel.com</email>
</author>
<published>2015-07-01T06:43:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a73aa5b5c7fff1778c5649c85b1b41d086c0d539'/>
<id>a73aa5b5c7fff1778c5649c85b1b41d086c0d539</id>
<content type='text'>
commit c04be18448355441a0c424362df65b6422e27bda upstream.

ACPICA commit 90f5332a15e9d9ba83831ca700b2b9f708274658

This patch adds a new FACS initialization flag for acpi_tb_initialize().
acpi_enable_subsystem() might be invoked several times in OS bootup process,
and we don't want FACS initialization to be invoked twice. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/90f5332a
Signed-off-by: Lv Zheng &lt;lv.zheng@intel.com&gt;
Signed-off-by: Bob Moore &lt;robert.moore@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c04be18448355441a0c424362df65b6422e27bda upstream.

ACPICA commit 90f5332a15e9d9ba83831ca700b2b9f708274658

This patch adds a new FACS initialization flag for acpi_tb_initialize().
acpi_enable_subsystem() might be invoked several times in OS bootup process,
and we don't want FACS initialization to be invoked twice. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/90f5332a
Signed-off-by: Lv Zheng &lt;lv.zheng@intel.com&gt;
Signed-off-by: Bob Moore &lt;robert.moore@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ACPICA: Tables: Change acpi_find_root_pointer() to use acpi_physical_address.</title>
<updated>2015-05-17T16:51:33+00:00</updated>
<author>
<name>Lv Zheng</name>
<email>lv.zheng@intel.com</email>
</author>
<published>2015-04-13T03:48:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=85e014b4304626972bff42249556748ad3fcf812'/>
<id>85e014b4304626972bff42249556748ad3fcf812</id>
<content type='text'>
commit f254e3c57b9d952e987502aefa0804c177dd2503 upstream.

ACPICA commit 7d9fd64397d7c38899d3dc497525f6e6b044e0e3

OSPMs like Linux expect an acpi_physical_address returning value from
acpi_find_root_pointer(). This triggers warnings if sizeof (acpi_size) doesn't
equal to sizeof (acpi_physical_address):
  drivers/acpi/osl.c:275:3: warning: passing argument 1 of 'acpi_find_root_pointer' from incompatible pointer type [enabled by default]
  In file included from include/acpi/acpi.h:64:0,
                   from include/linux/acpi.h:36,
                   from drivers/acpi/osl.c:41:
  include/acpi/acpixf.h:433:1: note: expected 'acpi_size *' but argument is of type 'acpi_physical_address *'
This patch corrects acpi_find_root_pointer().

Link: https://github.com/acpica/acpica/commit/7d9fd643
Signed-off-by: Lv Zheng &lt;lv.zheng@intel.com&gt;
Signed-off-by: Bob Moore &lt;robert.moore@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Dirk Behme &lt;dirk.behme@gmail.com&gt;
Signed-off-by: George G. Davis &lt;george_davis@mentor.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f254e3c57b9d952e987502aefa0804c177dd2503 upstream.

ACPICA commit 7d9fd64397d7c38899d3dc497525f6e6b044e0e3

OSPMs like Linux expect an acpi_physical_address returning value from
acpi_find_root_pointer(). This triggers warnings if sizeof (acpi_size) doesn't
equal to sizeof (acpi_physical_address):
  drivers/acpi/osl.c:275:3: warning: passing argument 1 of 'acpi_find_root_pointer' from incompatible pointer type [enabled by default]
  In file included from include/acpi/acpi.h:64:0,
                   from include/linux/acpi.h:36,
                   from drivers/acpi/osl.c:41:
  include/acpi/acpixf.h:433:1: note: expected 'acpi_size *' but argument is of type 'acpi_physical_address *'
This patch corrects acpi_find_root_pointer().

Link: https://github.com/acpica/acpica/commit/7d9fd643
Signed-off-by: Lv Zheng &lt;lv.zheng@intel.com&gt;
Signed-off-by: Bob Moore &lt;robert.moore@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Dirk Behme &lt;dirk.behme@gmail.com&gt;
Signed-off-by: George G. Davis &lt;george_davis@mentor.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ACPICA: Utilities: split IO address types from data type models.</title>
<updated>2015-05-06T19:56:26+00:00</updated>
<author>
<name>Lv Zheng</name>
<email>lv.zheng@intel.com</email>
</author>
<published>2015-04-13T03:48:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=27b22d0124993f4c321a3462946608dfd3512cda'/>
<id>27b22d0124993f4c321a3462946608dfd3512cda</id>
<content type='text'>
commit 2b8760100e1de69b6ff004c986328a82947db4ad upstream.

ACPICA commit aacf863cfffd46338e268b7415f7435cae93b451

It is reported that on a physically 64-bit addressed machine, 32-bit kernel
can trigger crashes in accessing the memory regions that are beyond the
32-bit boundary. The region field's start address should still be 32-bit
compliant, but after a calculation (adding some offsets), it may exceed the
32-bit boundary. This case is rare and buggy, but there are real BIOSes
leaked with such issues (see References below).

This patch fixes this gap by always defining IO addresses as 64-bit, and
allows OSPMs to optimize it for a real 32-bit machine to reduce the size of
the internal objects.

Internal acpi_physical_address usages in the structures that can be fixed
by this change include:
 1. struct acpi_object_region:
    acpi_physical_address		address;
 2. struct acpi_address_range:
    acpi_physical_address		start_address;
    acpi_physical_address		end_address;
 3. struct acpi_mem_space_context;
    acpi_physical_address		address;
 4. struct acpi_table_desc
    acpi_physical_address		address;
See known issues 1 for other usages.

Note that acpi_io_address which is used for ACPI_PROCESSOR may also suffer
from same problem, so this patch changes it accordingly.

For iasl, it will enforce acpi_physical_address as 32-bit to generate
32-bit OSPM compatible tables on 32-bit platforms, we need to define
ACPI_32BIT_PHYSICAL_ADDRESS for it in acenv.h.

Known issues:
 1. Cleanup of mapped virtual address
   In struct acpi_mem_space_context, acpi_physical_address is used as a virtual
   address:
    acpi_physical_address                   mapped_physical_address;
   It is better to introduce acpi_virtual_address or use acpi_size instead.
   This patch doesn't make such a change. Because this should be done along
   with a change to acpi_os_map_memory()/acpi_os_unmap_memory().
   There should be no functional problem to leave this unchanged except
   that only this structure is enlarged unexpectedly.

Link: https://github.com/acpica/acpica/commit/aacf863c
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=87971
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=79501
Reported-and-tested-by: Paul Menzel &lt;paulepanter@users.sourceforge.net&gt;
Reported-and-tested-by: Sial Nije &lt;sialnije@gmail.com&gt;
Signed-off-by: Lv Zheng &lt;lv.zheng@intel.com&gt;
Signed-off-by: Bob Moore &lt;robert.moore@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2b8760100e1de69b6ff004c986328a82947db4ad upstream.

ACPICA commit aacf863cfffd46338e268b7415f7435cae93b451

It is reported that on a physically 64-bit addressed machine, 32-bit kernel
can trigger crashes in accessing the memory regions that are beyond the
32-bit boundary. The region field's start address should still be 32-bit
compliant, but after a calculation (adding some offsets), it may exceed the
32-bit boundary. This case is rare and buggy, but there are real BIOSes
leaked with such issues (see References below).

This patch fixes this gap by always defining IO addresses as 64-bit, and
allows OSPMs to optimize it for a real 32-bit machine to reduce the size of
the internal objects.

Internal acpi_physical_address usages in the structures that can be fixed
by this change include:
 1. struct acpi_object_region:
    acpi_physical_address		address;
 2. struct acpi_address_range:
    acpi_physical_address		start_address;
    acpi_physical_address		end_address;
 3. struct acpi_mem_space_context;
    acpi_physical_address		address;
 4. struct acpi_table_desc
    acpi_physical_address		address;
See known issues 1 for other usages.

Note that acpi_io_address which is used for ACPI_PROCESSOR may also suffer
from same problem, so this patch changes it accordingly.

For iasl, it will enforce acpi_physical_address as 32-bit to generate
32-bit OSPM compatible tables on 32-bit platforms, we need to define
ACPI_32BIT_PHYSICAL_ADDRESS for it in acenv.h.

Known issues:
 1. Cleanup of mapped virtual address
   In struct acpi_mem_space_context, acpi_physical_address is used as a virtual
   address:
    acpi_physical_address                   mapped_physical_address;
   It is better to introduce acpi_virtual_address or use acpi_size instead.
   This patch doesn't make such a change. Because this should be done along
   with a change to acpi_os_map_memory()/acpi_os_unmap_memory().
   There should be no functional problem to leave this unchanged except
   that only this structure is enlarged unexpectedly.

Link: https://github.com/acpica/acpica/commit/aacf863c
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=87971
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=79501
Reported-and-tested-by: Paul Menzel &lt;paulepanter@users.sourceforge.net&gt;
Reported-and-tested-by: Sial Nije &lt;sialnije@gmail.com&gt;
Signed-off-by: Lv Zheng &lt;lv.zheng@intel.com&gt;
Signed-off-by: Bob Moore &lt;robert.moore@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / hotplug: Fix conflicted PCI bridge notify handlers</title>
<updated>2013-12-04T18:57:04+00:00</updated>
<author>
<name>Toshi Kani</name>
<email>toshi.kani@hp.com</email>
</author>
<published>2013-11-20T13:25:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1ba9563629aced9bd4471cd088fbffe11910e6f2'/>
<id>1ba9563629aced9bd4471cd088fbffe11910e6f2</id>
<content type='text'>
commit ca499fc87ed945094d952da0eb7eea7dbeb1feec upstream.

The PCI host bridge scan handler installs its own notify handler,
handle_hotplug_event_root(), by itself.  Nevertheless, the ACPI
hotplug framework also installs the common notify handler,
acpi_hotplug_notify_cb(), for PCI root bridges.  This causes
acpi_hotplug_notify_cb() to call _OST method with unsupported
error as hotplug.enabled is not set.

To address this issue, introduce hotplug.ignore flag, which
indicates that the scan handler installs its own notify handler by
itself.  The ACPI hotplug framework does not install the common
notify handler when this flag is set.

Signed-off-by: Toshi Kani &lt;toshi.kani@hp.com&gt;
[rjw: Changed the name of the new flag]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ca499fc87ed945094d952da0eb7eea7dbeb1feec upstream.

The PCI host bridge scan handler installs its own notify handler,
handle_hotplug_event_root(), by itself.  Nevertheless, the ACPI
hotplug framework also installs the common notify handler,
acpi_hotplug_notify_cb(), for PCI root bridges.  This causes
acpi_hotplug_notify_cb() to call _OST method with unsupported
error as hotplug.enabled is not set.

To address this issue, introduce hotplug.ignore flag, which
indicates that the scan handler installs its own notify handler by
itself.  The ACPI hotplug framework does not install the common
notify handler when this flag is set.

Signed-off-by: Toshi Kani &lt;toshi.kani@hp.com&gt;
[rjw: Changed the name of the new flag]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: Try harder to resolve _ADR collisions for bridges</title>
<updated>2013-08-29T16:47:29+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-08-07T20:55:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6e4fdb803584635587bd4dc00d1f8c0883a02d3b'/>
<id>6e4fdb803584635587bd4dc00d1f8c0883a02d3b</id>
<content type='text'>
commit 60f75b8e97daf4a39790a20d962cb861b9220af5 upstream.

In theory, under a given ACPI namespace node there should be only
one child device object with _ADR whose value matches a given bus
address exactly.  In practice, however, there are systems in which
multiple child device objects under a given parent have _ADR matching
exactly the same address.  In those cases we use _STA to determine
which of the multiple matching devices is enabled, since some systems
are known to indicate which ACPI device object to associate with the
given physical (usually PCI) device this way.

Unfortunately, as it turns out, there are systems in which many
device objects under the same parent have _ADR matching exactly the
same bus address and none of them has _STA, in which case they all
should be regarded as enabled according to the spec.  Still, if
those device objects are supposed to represent bridges (e.g. this
is the case for device objects corresponding to PCIe ports), we can
try harder and skip the ones that have no child device objects in the
ACPI namespace.  With luck, we can avoid using device objects that we
are not expected to use this way.

Although this only works for bridges whose children also have ACPI
namespace representation, it is sufficient to address graphics
adapter detection issues on some systems, so rework the code finding
a matching device ACPI handle for a given bus address to implement
this idea.

Introduce a new function, acpi_find_child(), taking three arguments:
the ACPI handle of the device's parent, a bus address suitable for
the device's bus type and a bool indicating if the device is a
bridge and make it work as outlined above.  Reimplement the function
currently used for this purpose, acpi_get_child(), as a call to
acpi_find_child() with the last argument set to 'false' and make
the PCI subsystem use acpi_find_child() with the bridge information
passed as the last argument to it.  [Lan Tianyu notices that it is
not sufficient to use pci_is_bridge() for that, because the device's
subordinate pointer hasn't been set yet at this point, so use
hdr_type instead.]

This change fixes a regression introduced inadvertently by commit
33f767d (ACPI: Rework acpi_get_child() to be more efficient) which
overlooked the fact that for acpi_walk_namespace() "post-order" means
"after all children have been visited" rather than "on the way back",
so for device objects without children and for namespace walks of
depth 1, as in the acpi_get_child() case, the "post-order" callbacks
ordering is actually the same as the ordering of "pre-order" ones.
Since that commit changed the namespace walk in acpi_get_child() to
terminate after finding the first matching object instead of going
through all of them and returning the last one, it effectively
changed the result returned by that function in some rare cases and
that led to problems (the switch from a "pre-order" to a "post-order"
callback was supposed to prevent that from happening, but it was
ineffective).

As it turns out, the systems where the change made by commit
33f767d actually matters are those where there are multiple ACPI
device objects representing the same PCIe port (which effectively
is a bridge).  Moreover, only one of them, and the one we are
expected to use, has child device objects in the ACPI namespace,
so the regression can be addressed as described above.

References: https://bugzilla.kernel.org/show_bug.cgi?id=60561
Reported-by: Peter Wu &lt;lekensteyn@gmail.com&gt;
Tested-by: Vladimir Lalov &lt;mail@vlalov.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Peter Wu &lt;lekensteyn@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 60f75b8e97daf4a39790a20d962cb861b9220af5 upstream.

In theory, under a given ACPI namespace node there should be only
one child device object with _ADR whose value matches a given bus
address exactly.  In practice, however, there are systems in which
multiple child device objects under a given parent have _ADR matching
exactly the same address.  In those cases we use _STA to determine
which of the multiple matching devices is enabled, since some systems
are known to indicate which ACPI device object to associate with the
given physical (usually PCI) device this way.

Unfortunately, as it turns out, there are systems in which many
device objects under the same parent have _ADR matching exactly the
same bus address and none of them has _STA, in which case they all
should be regarded as enabled according to the spec.  Still, if
those device objects are supposed to represent bridges (e.g. this
is the case for device objects corresponding to PCIe ports), we can
try harder and skip the ones that have no child device objects in the
ACPI namespace.  With luck, we can avoid using device objects that we
are not expected to use this way.

Although this only works for bridges whose children also have ACPI
namespace representation, it is sufficient to address graphics
adapter detection issues on some systems, so rework the code finding
a matching device ACPI handle for a given bus address to implement
this idea.

Introduce a new function, acpi_find_child(), taking three arguments:
the ACPI handle of the device's parent, a bus address suitable for
the device's bus type and a bool indicating if the device is a
bridge and make it work as outlined above.  Reimplement the function
currently used for this purpose, acpi_get_child(), as a call to
acpi_find_child() with the last argument set to 'false' and make
the PCI subsystem use acpi_find_child() with the bridge information
passed as the last argument to it.  [Lan Tianyu notices that it is
not sufficient to use pci_is_bridge() for that, because the device's
subordinate pointer hasn't been set yet at this point, so use
hdr_type instead.]

This change fixes a regression introduced inadvertently by commit
33f767d (ACPI: Rework acpi_get_child() to be more efficient) which
overlooked the fact that for acpi_walk_namespace() "post-order" means
"after all children have been visited" rather than "on the way back",
so for device objects without children and for namespace walks of
depth 1, as in the acpi_get_child() case, the "post-order" callbacks
ordering is actually the same as the ordering of "pre-order" ones.
Since that commit changed the namespace walk in acpi_get_child() to
terminate after finding the first matching object instead of going
through all of them and returning the last one, it effectively
changed the result returned by that function in some rare cases and
that led to problems (the switch from a "pre-order" to a "post-order"
callback was supposed to prevent that from happening, but it was
ineffective).

As it turns out, the systems where the change made by commit
33f767d actually matters are those where there are multiple ACPI
device objects representing the same PCIe port (which effectively
is a bridge).  Moreover, only one of them, and the one we are
expected to use, has child device objects in the ACPI namespace,
so the regression can be addressed as described above.

References: https://bugzilla.kernel.org/show_bug.cgi?id=60561
Reported-by: Peter Wu &lt;lekensteyn@gmail.com&gt;
Tested-by: Vladimir Lalov &lt;mail@vlalov.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Peter Wu &lt;lekensteyn@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / dock / PCI: Synchronous handling of dock events for PCI devices</title>
<updated>2013-06-24T09:22:53+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-06-24T09:22:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=21a31013f774c726bd199526cd673acc6432b21d'/>
<id>21a31013f774c726bd199526cd673acc6432b21d</id>
<content type='text'>
The interactions between the ACPI dock driver and the ACPI-based PCI
hotplug (acpiphp) are currently problematic because of ordering
issues during hot-remove operations.

First of all, the current ACPI glue code expects that physical
devices will always be deleted before deleting the companion ACPI
device objects.  Otherwise, acpi_unbind_one() will fail with a
warning message printed to the kernel log, for example:

[  185.026073] usb usb5: Oops, 'acpi_handle' corrupt
[  185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
[  185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
[  180.013656]  port1: Oops, 'acpi_handle' corrupt

This means, in particular, that struct pci_dev objects have to
be deleted before the struct acpi_device objects they are "glued"
with.

Now, the following happens the during the undocking of an ACPI-based
dock station:
 1) hotplug_dock_devices() invokes registered hotplug callbacks to
    destroy physical devices associated with the ACPI device objects
    depending on the dock station.  It calls dd-&gt;ops-&gt;handler() for
    each of those device objects.
 2) For PCI devices dd-&gt;ops-&gt;handler() points to
    handle_hotplug_event_func() that queues up a separate work item
    to execute _handle_hotplug_event_func() for the given device and
    returns immediately.  That work item will be executed later.
 3) hotplug_dock_devices() calls dock_remove_acpi_device() for each
    device depending on the dock station.  This runs acpi_bus_trim()
    for each of them, which causes the underlying ACPI device object
    to be destroyed, but the work items queued up by
    handle_hotplug_event_func() haven't been started yet.
 4) _handle_hotplug_event_func() queued up in step 2) are executed
    and cause the above failure to happen, because the PCI devices
    they handle do not have the companion ACPI device objects any
    more (those objects have been deleted in step 3).

The possible breakage doesn't end here, though, because
hotplug_dock_devices() may return before at least some of the
_handle_hotplug_event_func() work items spawned by it have a
chance to complete and then undock() will cause _DCK to be
evaluated and that will cause the devices handled by the
_handle_hotplug_event_func() to go away possibly while they are
being accessed.

This means that dd-&gt;ops-&gt;handler() for PCI devices should not point
to handle_hotplug_event_func().  Instead, it should point to a
function that will do the work of _handle_hotplug_event_func()
synchronously.  For this reason, introduce such a function,
hotplug_event_func(), and modity acpiphp_dock_ops to point to
it as the handler.

Unfortunately, however, this is not sufficient, because if the dock
code were not changed further, hotplug_event_func() would now
deadlock with hotplug_dock_devices() that called it, since it would
run unregister_hotplug_dock_device() which in turn would attempt to
acquire the dock station's hp_lock mutex already acquired by
hotplug_dock_devices().

To resolve that deadlock use the observation that
unregister_hotplug_dock_device() won't need to acquire hp_lock
if PCI bridges the devices on the dock station depend on are
prevented from being removed prematurely while the first loop in
hotplug_dock_devices() is in progress.

To make that possible, introduce a mechanism by which the callers of
register_hotplug_dock_device() can provide "init" and "release"
routines that will be executed, respectively, during the addition
and removal of the physical device object associated with the
given ACPI device handle.  Make acpiphp use two new functions,
acpiphp_dock_init() and acpiphp_dock_release(), that call
get_bridge() and put_bridge(), respectively, on the acpiphp bridge
holding the given device, for this purpose.

In addition to that, remove the dock station's list of
"hotplug devices" and make the dock code always walk the whole list
of "dependent devices" instead in such a way that the loops in
hotplug_dock_devices() and dock_event() (replacing the loops over
"hotplug devices") will take references to the list entries that
register_hotplug_dock_device() has been called for.  That prevents
the "release" routines associated with those entries from being
called while the given entry is being processed and for PCI
devices this means that their bridges won't be removed (by a
concurrent thread) while hotplug_event_func() handling them is
being executed.

This change is based on two earlier patches from Jiang Liu.

References: https://bugzilla.kernel.org/show_bug.cgi?id=59501
Reported-and-tested-by: Alexander E. Patrakov &lt;patrakov@gmail.com&gt;
Tracked-down-by: Jiang Liu &lt;jiang.liu@huawei.com&gt;
Tested-by: Illya Klymov &lt;xanf@xanf.me&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Cc: 3.9+ &lt;stable@vger.kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The interactions between the ACPI dock driver and the ACPI-based PCI
hotplug (acpiphp) are currently problematic because of ordering
issues during hot-remove operations.

First of all, the current ACPI glue code expects that physical
devices will always be deleted before deleting the companion ACPI
device objects.  Otherwise, acpi_unbind_one() will fail with a
warning message printed to the kernel log, for example:

[  185.026073] usb usb5: Oops, 'acpi_handle' corrupt
[  185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
[  185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
[  180.013656]  port1: Oops, 'acpi_handle' corrupt

This means, in particular, that struct pci_dev objects have to
be deleted before the struct acpi_device objects they are "glued"
with.

Now, the following happens the during the undocking of an ACPI-based
dock station:
 1) hotplug_dock_devices() invokes registered hotplug callbacks to
    destroy physical devices associated with the ACPI device objects
    depending on the dock station.  It calls dd-&gt;ops-&gt;handler() for
    each of those device objects.
 2) For PCI devices dd-&gt;ops-&gt;handler() points to
    handle_hotplug_event_func() that queues up a separate work item
    to execute _handle_hotplug_event_func() for the given device and
    returns immediately.  That work item will be executed later.
 3) hotplug_dock_devices() calls dock_remove_acpi_device() for each
    device depending on the dock station.  This runs acpi_bus_trim()
    for each of them, which causes the underlying ACPI device object
    to be destroyed, but the work items queued up by
    handle_hotplug_event_func() haven't been started yet.
 4) _handle_hotplug_event_func() queued up in step 2) are executed
    and cause the above failure to happen, because the PCI devices
    they handle do not have the companion ACPI device objects any
    more (those objects have been deleted in step 3).

The possible breakage doesn't end here, though, because
hotplug_dock_devices() may return before at least some of the
_handle_hotplug_event_func() work items spawned by it have a
chance to complete and then undock() will cause _DCK to be
evaluated and that will cause the devices handled by the
_handle_hotplug_event_func() to go away possibly while they are
being accessed.

This means that dd-&gt;ops-&gt;handler() for PCI devices should not point
to handle_hotplug_event_func().  Instead, it should point to a
function that will do the work of _handle_hotplug_event_func()
synchronously.  For this reason, introduce such a function,
hotplug_event_func(), and modity acpiphp_dock_ops to point to
it as the handler.

Unfortunately, however, this is not sufficient, because if the dock
code were not changed further, hotplug_event_func() would now
deadlock with hotplug_dock_devices() that called it, since it would
run unregister_hotplug_dock_device() which in turn would attempt to
acquire the dock station's hp_lock mutex already acquired by
hotplug_dock_devices().

To resolve that deadlock use the observation that
unregister_hotplug_dock_device() won't need to acquire hp_lock
if PCI bridges the devices on the dock station depend on are
prevented from being removed prematurely while the first loop in
hotplug_dock_devices() is in progress.

To make that possible, introduce a mechanism by which the callers of
register_hotplug_dock_device() can provide "init" and "release"
routines that will be executed, respectively, during the addition
and removal of the physical device object associated with the
given ACPI device handle.  Make acpiphp use two new functions,
acpiphp_dock_init() and acpiphp_dock_release(), that call
get_bridge() and put_bridge(), respectively, on the acpiphp bridge
holding the given device, for this purpose.

In addition to that, remove the dock station's list of
"hotplug devices" and make the dock code always walk the whole list
of "dependent devices" instead in such a way that the loops in
hotplug_dock_devices() and dock_event() (replacing the loops over
"hotplug devices") will take references to the list entries that
register_hotplug_dock_device() has been called for.  That prevents
the "release" routines associated with those entries from being
called while the given entry is being processed and for PCI
devices this means that their bridges won't be removed (by a
concurrent thread) while hotplug_event_func() handling them is
being executed.

This change is based on two earlier patches from Jiang Liu.

References: https://bugzilla.kernel.org/show_bug.cgi?id=59501
Reported-and-tested-by: Alexander E. Patrakov &lt;patrakov@gmail.com&gt;
Tracked-down-by: Jiang Liu &lt;jiang.liu@huawei.com&gt;
Tested-by: Illya Klymov &lt;xanf@xanf.me&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Cc: 3.9+ &lt;stable@vger.kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / LPSS: Power up LPSS devices during enumeration</title>
<updated>2013-06-19T22:49:06+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-06-18T22:45:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b9e95fc65ededbec083aa91b4faa58ad992c0891'/>
<id>b9e95fc65ededbec083aa91b4faa58ad992c0891</id>
<content type='text'>
Commit 7cd8407 (ACPI / PM: Do not execute _PS0 for devices without
_PSC during initialization) introduced a regression on some systems
with Intel Lynxpoint Low-Power Subsystem (LPSS) where some devices
need to be powered up during initialization, but their device objects
in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power
resources).

To work around this problem, make the ACPI LPSS driver power up
devices it knows about by using a new helper function
acpi_device_fix_up_power() that does all of the necessary
sanity checks and calls acpi_dev_pm_explicit_set() to put the
device into D0.

Reported-and-tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&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 7cd8407 (ACPI / PM: Do not execute _PS0 for devices without
_PSC during initialization) introduced a regression on some systems
with Intel Lynxpoint Low-Power Subsystem (LPSS) where some devices
need to be powered up during initialization, but their device objects
in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power
resources).

To work around this problem, make the ACPI LPSS driver power up
devices it knows about by using a new helper function
acpi_device_fix_up_power() that does all of the necessary
sanity checks and calls acpi_dev_pm_explicit_set() to put the
device into D0.

Reported-and-tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PM: Allow device power states to be used for CONFIG_PM unset</title>
<updated>2013-05-21T22:19:28+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-05-16T20:29:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ec4602a9588a196fa1a9af46bfdd37cbf5792db4'/>
<id>ec4602a9588a196fa1a9af46bfdd37cbf5792db4</id>
<content type='text'>
Currently, drivers/acpi/device_pm.c depends on CONFIG_PM and all of
the functions defined in there are replaced with static inline stubs
if that option is unset.  However, CONFIG_PM means, roughly, "runtime
PM or suspend/hibernation support" and some of those functions are
useful regardless of that.  For example, they are used by the ACPI
fan driver for controlling fans and acpi_device_set_power() is called
during device removal.  Moreover, device initialization may depend on
setting device power states properly.

For these reasons, make the routines manipulating ACPI device power
states defined in drivers/acpi/device_pm.c available for CONFIG_PM
unset too.

Reported-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Reported-and-tested-by: Michel Lespinasse &lt;walken@google.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: 3.9+ &lt;stable@vger.kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, drivers/acpi/device_pm.c depends on CONFIG_PM and all of
the functions defined in there are replaced with static inline stubs
if that option is unset.  However, CONFIG_PM means, roughly, "runtime
PM or suspend/hibernation support" and some of those functions are
useful regardless of that.  For example, they are used by the ACPI
fan driver for controlling fans and acpi_device_set_power() is called
during device removal.  Moreover, device initialization may depend on
setting device power states properly.

For these reasons, make the routines manipulating ACPI device power
states defined in drivers/acpi/device_pm.c available for CONFIG_PM
unset too.

Reported-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Reported-and-tested-by: Michel Lespinasse &lt;walken@google.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: 3.9+ &lt;stable@vger.kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: Fix section to __init. Align with usage in acpixf.h</title>
<updated>2013-05-12T12:03:14+00:00</updated>
<author>
<name>Jan-Simon Möller</name>
<email>dl9pf@gmx.de</email>
</author>
<published>2013-04-30T09:39:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=36200af867e2cf5adc1ff77214b2524f6111736f'/>
<id>36200af867e2cf5adc1ff77214b2524f6111736f</id>
<content type='text'>
Fixes warning during compilation with clang.

[rjw: Subject and changelog]
Signed-off-by: Jan-Simon Möller &lt;dl9pf@gmx.de&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>
Fixes warning during compilation with clang.

[rjw: Subject and changelog]
Signed-off-by: Jan-Simon Möller &lt;dl9pf@gmx.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PM: Move processor suspend/resume to syscore_ops</title>
<updated>2013-05-12T12:03:14+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-05-02T19:54:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0a3b15ac3cc3ddc791901e12bdc930b5fa11a30a'/>
<id>0a3b15ac3cc3ddc791901e12bdc930b5fa11a30a</id>
<content type='text'>
The system suspend routine of the ACPI processor driver saves
the BUS_MASTER_RLD register and its resume routine restores it.
However, there can be only one such register in the system and it
really should be saved after non-boot CPUs have been offlined and
restored before they are put back online during resume.

For this reason, move the saving and restoration of BUS_MASTER_RLD
to syscore suspend and syscore resume, respectively, and drop the no
longer necessary suspend/resume callbacks from the ACPI processor
driver.

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>
The system suspend routine of the ACPI processor driver saves
the BUS_MASTER_RLD register and its resume routine restores it.
However, there can be only one such register in the system and it
really should be saved after non-boot CPUs have been offlined and
restored before they are put back online during resume.

For this reason, move the saving and restoration of BUS_MASTER_RLD
to syscore suspend and syscore resume, respectively, and drop the no
longer necessary suspend/resume callbacks from the ACPI processor
driver.

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