<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/acpi, branch v6.1.168</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>ACPI: EC: Evaluate orphan _REG under EC device</title>
<updated>2026-04-11T12:16:39+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2024-06-12T14:15:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d65abd8282fcaceeee8794859b1ec8cf062f42f4'/>
<id>d65abd8282fcaceeee8794859b1ec8cf062f42f4</id>
<content type='text'>
commit 0e6b6dedf16800df0ff73ffe2bb5066514db29c2 upstream.

After starting to install the EC address space handler at the ACPI
namespace root, if there is an "orphan" _REG method in the EC device's
scope, it will not be evaluated any more.  This breaks EC operation
regions on some systems, like Asus gu605.

To address this, use a wrapper around an existing ACPICA function to
look for an "orphan" _REG method in the EC device scope and evaluate
it if present.

Fixes: 60fa6ae6e6d0 ("ACPI: EC: Install address space handler at the namespace root")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218945
Reported-by: VitaliiT &lt;vitaly.torshyn@gmail.com&gt;
Tested-by: VitaliiT &lt;vitaly.torshyn@gmail.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 0e6b6dedf16800df0ff73ffe2bb5066514db29c2 upstream.

After starting to install the EC address space handler at the ACPI
namespace root, if there is an "orphan" _REG method in the EC device's
scope, it will not be evaluated any more.  This breaks EC operation
regions on some systems, like Asus gu605.

To address this, use a wrapper around an existing ACPICA function to
look for an "orphan" _REG method in the EC device scope and evaluate
it if present.

Fixes: 60fa6ae6e6d0 ("ACPI: EC: Install address space handler at the namespace root")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218945
Reported-by: VitaliiT &lt;vitaly.torshyn@gmail.com&gt;
Tested-by: VitaliiT &lt;vitaly.torshyn@gmail.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: EC: clean up handlers on probe failure in acpi_ec_setup()</title>
<updated>2026-04-11T12:16:12+00:00</updated>
<author>
<name>Weiming Shi</name>
<email>bestswngs@gmail.com</email>
</author>
<published>2026-03-24T16:54:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=022d1727f33ff90b3e1775125264e3023901952e'/>
<id>022d1727f33ff90b3e1775125264e3023901952e</id>
<content type='text'>
[ Upstream commit f6484cadbcaf26b5844b51bd7307a663dda48ef6 ]

When ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware
platforms, it has already started the EC and installed the address
space handler with the struct acpi_ec pointer as handler context.
However, acpi_ec_setup() propagates the error without any cleanup.

The caller acpi_ec_add() then frees the struct acpi_ec for non-boot
instances, leaving a dangling handler context in ACPICA.

Any subsequent AML evaluation that accesses an EC OpRegion field
dispatches into acpi_ec_space_handler() with the freed pointer,
causing a use-after-free:

 BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289)
 Write of size 8 at addr ffff88800721de38 by task init/1
 Call Trace:
  &lt;TASK&gt;
  mutex_lock (kernel/locking/mutex.c:289)
  acpi_ec_space_handler (drivers/acpi/ec.c:1362)
  acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293)
  acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246)
  acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509)
  acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700)
  acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327)
  acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392)
  &lt;/TASK&gt;

 Allocated by task 1:
  acpi_ec_alloc (drivers/acpi/ec.c:1424)
  acpi_ec_add (drivers/acpi/ec.c:1692)

 Freed by task 1:
  kfree (mm/slub.c:6876)
  acpi_ec_add (drivers/acpi/ec.c:1751)

The bug triggers on reduced-hardware EC platforms (ec-&gt;gpe &lt; 0)
when the GPIO IRQ provider defers probing. Once the stale handler
exists, any unprivileged sysfs read that causes AML to touch an
EC OpRegion (battery, thermal, backlight) exercises the dangling
pointer.

Fix this by calling ec_remove_handlers() in the error path of
acpi_ec_setup() before clearing first_ec. ec_remove_handlers()
checks each EC_FLAGS_* bit before acting, so it is safe to call
regardless of how far ec_install_handlers() progressed:

  -ENODEV  (handler not installed): only calls acpi_ec_stop()
  -EPROBE_DEFER (handler installed): removes handler, stops EC

Fixes: 03e9a0e05739 ("ACPI: EC: Consolidate event handler installation code")
Reported-by: Xiang Mei &lt;xmei5@asu.edu&gt;
Signed-off-by: Weiming Shi &lt;bestswngs@gmail.com&gt;
Link: https://patch.msgid.link/20260324165458.1337233-2-bestswngs@gmail.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f6484cadbcaf26b5844b51bd7307a663dda48ef6 ]

When ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware
platforms, it has already started the EC and installed the address
space handler with the struct acpi_ec pointer as handler context.
However, acpi_ec_setup() propagates the error without any cleanup.

The caller acpi_ec_add() then frees the struct acpi_ec for non-boot
instances, leaving a dangling handler context in ACPICA.

Any subsequent AML evaluation that accesses an EC OpRegion field
dispatches into acpi_ec_space_handler() with the freed pointer,
causing a use-after-free:

 BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289)
 Write of size 8 at addr ffff88800721de38 by task init/1
 Call Trace:
  &lt;TASK&gt;
  mutex_lock (kernel/locking/mutex.c:289)
  acpi_ec_space_handler (drivers/acpi/ec.c:1362)
  acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293)
  acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246)
  acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509)
  acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700)
  acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327)
  acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392)
  &lt;/TASK&gt;

 Allocated by task 1:
  acpi_ec_alloc (drivers/acpi/ec.c:1424)
  acpi_ec_add (drivers/acpi/ec.c:1692)

 Freed by task 1:
  kfree (mm/slub.c:6876)
  acpi_ec_add (drivers/acpi/ec.c:1751)

The bug triggers on reduced-hardware EC platforms (ec-&gt;gpe &lt; 0)
when the GPIO IRQ provider defers probing. Once the stale handler
exists, any unprivileged sysfs read that causes AML to touch an
EC OpRegion (battery, thermal, backlight) exercises the dangling
pointer.

Fix this by calling ec_remove_handlers() in the error path of
acpi_ec_setup() before clearing first_ec. ec_remove_handlers()
checks each EC_FLAGS_* bit before acting, so it is safe to call
regardless of how far ec_install_handlers() progressed:

  -ENODEV  (handler not installed): only calls acpi_ec_stop()
  -EPROBE_DEFER (handler installed): removes handler, stops EC

Fixes: 03e9a0e05739 ("ACPI: EC: Consolidate event handler installation code")
Reported-by: Xiang Mei &lt;xmei5@asu.edu&gt;
Signed-off-by: Weiming Shi &lt;bestswngs@gmail.com&gt;
Link: https://patch.msgid.link/20260324165458.1337233-2-bestswngs@gmail.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: Install address space handler at the namespace root</title>
<updated>2026-04-11T12:16:12+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2024-05-15T19:40:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=3dd5ace4d5e7a02b3e70d2ee0094c4f5b7fe8f70'/>
<id>3dd5ace4d5e7a02b3e70d2ee0094c4f5b7fe8f70</id>
<content type='text'>
[ Upstream commit 60fa6ae6e6d09e377fce6f8d9b6f6a4d88769f63 ]

It is reported that _DSM evaluation fails in ucsi_acpi_dsm() on Lenovo
IdeaPad Pro 5 due to a missing address space handler for the EC address
space:

 ACPI Error: No handler for Region [ECSI] (000000007b8176ee) [EmbeddedControl] (20230628/evregion-130)

This happens because if there is no ECDT, the EC driver only registers
the EC address space handler for operation regions defined in the EC
device scope of the ACPI namespace while the operation region being
accessed by the _DSM in question is located beyond that scope.

To address this, modify the ACPI EC driver to install the EC address
space handler at the root of the ACPI namespace for the first EC that
can be found regardless of whether or not an ECDT is present.

Note that this change is consistent with some examples in the ACPI
specification in which EC operation regions located outside the EC
device scope are used (for example, see Section 9.17.15 in ACPI 6.5),
so the current behavior of the EC driver is arguably questionable.

Reported-by: webcaptcha &lt;webcapcha@gmail.com&gt;
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218789
Link: https://uefi.org/specs/ACPI/6.5/09_ACPI_Defined_Devices_and_Device_Specific_Objects.html#example-asl-code
Link: https://lore.kernel.org/linux-acpi/Zi+0whTvDbAdveHq@kuha.fi.intel.com
Suggested-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 60fa6ae6e6d09e377fce6f8d9b6f6a4d88769f63 ]

It is reported that _DSM evaluation fails in ucsi_acpi_dsm() on Lenovo
IdeaPad Pro 5 due to a missing address space handler for the EC address
space:

 ACPI Error: No handler for Region [ECSI] (000000007b8176ee) [EmbeddedControl] (20230628/evregion-130)

This happens because if there is no ECDT, the EC driver only registers
the EC address space handler for operation regions defined in the EC
device scope of the ACPI namespace while the operation region being
accessed by the _DSM in question is located beyond that scope.

To address this, modify the ACPI EC driver to install the EC address
space handler at the root of the ACPI namespace for the first EC that
can be found regardless of whether or not an ECDT is present.

Note that this change is consistent with some examples in the ACPI
specification in which EC operation regions located outside the EC
device scope are used (for example, see Section 9.17.15 in ACPI 6.5),
so the current behavior of the EC driver is arguably questionable.

Reported-by: webcaptcha &lt;webcapcha@gmail.com&gt;
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218789
Link: https://uefi.org/specs/ACPI/6.5/09_ACPI_Defined_Devices_and_Device_Specific_Objects.html#example-asl-code
Link: https://lore.kernel.org/linux-acpi/Zi+0whTvDbAdveHq@kuha.fi.intel.com
Suggested-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: Fix ECDT probe ordering issues</title>
<updated>2026-04-11T12:16:11+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2022-12-08T14:23:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=af9c1062ac2fbf56226c5d195bd8b00b321e78cb'/>
<id>af9c1062ac2fbf56226c5d195bd8b00b321e78cb</id>
<content type='text'>
[ Upstream commit ab4620f58d38206687b9f99d9d2cc1d5a2640985 ]

ACPI-2.0 says that the EC OpRegion handler must be available immediately
(like the standard default OpRegion handlers):

Quoting from the ACPI spec version 6.3: "6.5.4 _REG (Region) ...
2. OSPM must make Embedded Controller operation regions, accessed via
the Embedded Controllers described in ECDT, available before executing
any control method. These operation regions may become inaccessible
after OSPM runs _REG(EmbeddedControl, 0)."

So acpi_bus_init() calls acpi_ec_ecdt_probe(), which calls
acpi_install_address_space_handler() to install the EC's OpRegion
handler, early on.

This not only installs the OpRegion handler, but also calls the EC's
_REG method. The _REG method call is a problem because it may rely on
initialization done by the _INI methods of one of the PCI / _SB root devs,
see for example: https://bugzilla.kernel.org/show_bug.cgi?id=214899 .

Generally speaking _REG methods are executed when the ACPI-device they
are part of has a driver bound to it. Where as _INI methods must be
executed at table load time (according to the spec). The problem here
is that the early acpi_install_address_space_handler() call causes
the _REG handler to run too early.

To allow fixing this the ACPICA code now allows to split the OpRegion
handler installation and the executing of _REG into 2 separate steps.

This commit uses this ACPICA functionality to fix the EC probe ordering
by delaying the executing of _REG for ECDT described ECs till the matching
EC device in the DSDT gets parsed and acpi_ec_add() for it gets called.
This moves the calling of _REG for the EC on devices with an ECDT to
the same point in time where it is called on devices without an ECDT table.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=214899
Reported-and-tested-by: Johannes Penßel &lt;johannespenssel@posteo.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ab4620f58d38206687b9f99d9d2cc1d5a2640985 ]

ACPI-2.0 says that the EC OpRegion handler must be available immediately
(like the standard default OpRegion handlers):

Quoting from the ACPI spec version 6.3: "6.5.4 _REG (Region) ...
2. OSPM must make Embedded Controller operation regions, accessed via
the Embedded Controllers described in ECDT, available before executing
any control method. These operation regions may become inaccessible
after OSPM runs _REG(EmbeddedControl, 0)."

So acpi_bus_init() calls acpi_ec_ecdt_probe(), which calls
acpi_install_address_space_handler() to install the EC's OpRegion
handler, early on.

This not only installs the OpRegion handler, but also calls the EC's
_REG method. The _REG method call is a problem because it may rely on
initialization done by the _INI methods of one of the PCI / _SB root devs,
see for example: https://bugzilla.kernel.org/show_bug.cgi?id=214899 .

Generally speaking _REG methods are executed when the ACPI-device they
are part of has a driver bound to it. Where as _INI methods must be
executed at table load time (according to the spec). The problem here
is that the early acpi_install_address_space_handler() call causes
the _REG handler to run too early.

To allow fixing this the ACPICA code now allows to split the OpRegion
handler installation and the executing of _REG into 2 separate steps.

This commit uses this ACPICA functionality to fix the EC probe ordering
by delaying the executing of _REG for ECDT described ECs till the matching
EC device in the DSDT gets parsed and acpi_ec_add() for it gets called.
This moves the calling of _REG for the EC on devices with an ECDT to
the same point in time where it is called on devices without an ECDT table.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=214899
Reported-and-tested-by: Johannes Penßel &lt;johannespenssel@posteo.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: Fix EC address space handler unregistration</title>
<updated>2026-04-11T12:16:11+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2022-12-08T14:23:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=c105ef4311da6e26494b02abcb64475213d8569b'/>
<id>c105ef4311da6e26494b02abcb64475213d8569b</id>
<content type='text'>
[ Upstream commit a5072078dbfaa9d70130805766dfa34bbb7bf2a7 ]

When an ECDT table is present the EC address space handler gets registered
on the root node. So to unregister it properly the unregister call also
must be done on the root node.

Store the ACPI handle used for the acpi_install_address_space_handler()
call and use te same handle for the acpi_remove_address_space_handler()
call.

Reported-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a5072078dbfaa9d70130805766dfa34bbb7bf2a7 ]

When an ECDT table is present the EC address space handler gets registered
on the root node. So to unregister it properly the unregister call also
must be done on the root node.

Store the ACPI handle used for the acpi_install_address_space_handler()
call and use te same handle for the acpi_remove_address_space_handler()
call.

Reported-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPICA: Allow address_space_handler Install and _REG execution as 2 separate steps</title>
<updated>2026-04-11T12:16:11+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2022-12-08T14:23:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=8191322a1efc0169213217bd7844c3f146b56ef1'/>
<id>8191322a1efc0169213217bd7844c3f146b56ef1</id>
<content type='text'>
[ Upstream commit 54c516aeb8b39eeae6450b7d8076d381568dca46 ]

ACPI-2.0 says that the EC op_region handler must be available immediately
(like the standard default op_region handlers):

Quoting from the ACPI spec version 6.3: "6.5.4 _REG (Region) ...
2. OSPM must make Embedded Controller operation regions, accessed via
the Embedded Controllers described in ECDT, available before executing
any control method. These operation regions may become inaccessible
after OSPM runs _REG(EmbeddedControl, 0)."

So the OS must probe the ECDT described EC and install the OpRegion handler
before calling acpi_enable_subsystem() and acpi_initialize_objects().

This is a problem because calling acpi_install_address_space_handler()
does not just install the op_region handler, it also runs the EC's _REG
method. This _REG method may rely on initialization done by the _INI
methods of one of the PCI / _SB root devices.

For the other early/default op_region handlers the op_region handler
install and the _REG execution is split into 2 separate steps:
1. acpi_ev_install_region_handlers(), called early from acpi_load_tables()
2. acpi_ev_initialize_op_regions(), called from acpi_initialize_objects()

To fix the EC op_region issue, add 2 bew functions:
1. acpi_install_address_space_handler_no_reg()
2. acpi_execute_reg_methods()
to allow doing things in 2 steps for other op_region handlers,
like the EC handler, too.

Note that the comment describing acpi_ev_install_region_handlers() even has
an alinea describing this problem. Using the new methods allows users
to avoid this problem.

Link: https://github.com/acpica/acpica/pull/786
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214899
Reported-and-tested-by: Johannes Penßel &lt;johannespenssel@posteo.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 54c516aeb8b39eeae6450b7d8076d381568dca46 ]

ACPI-2.0 says that the EC op_region handler must be available immediately
(like the standard default op_region handlers):

Quoting from the ACPI spec version 6.3: "6.5.4 _REG (Region) ...
2. OSPM must make Embedded Controller operation regions, accessed via
the Embedded Controllers described in ECDT, available before executing
any control method. These operation regions may become inaccessible
after OSPM runs _REG(EmbeddedControl, 0)."

So the OS must probe the ECDT described EC and install the OpRegion handler
before calling acpi_enable_subsystem() and acpi_initialize_objects().

This is a problem because calling acpi_install_address_space_handler()
does not just install the op_region handler, it also runs the EC's _REG
method. This _REG method may rely on initialization done by the _INI
methods of one of the PCI / _SB root devices.

For the other early/default op_region handlers the op_region handler
install and the _REG execution is split into 2 separate steps:
1. acpi_ev_install_region_handlers(), called early from acpi_load_tables()
2. acpi_ev_initialize_op_regions(), called from acpi_initialize_objects()

To fix the EC op_region issue, add 2 bew functions:
1. acpi_install_address_space_handler_no_reg()
2. acpi_execute_reg_methods()
to allow doing things in 2 steps for other op_region handlers,
like the EC handler, too.

Note that the comment describing acpi_ev_install_region_handlers() even has
an alinea describing this problem. Using the new methods allows users
to avoid this problem.

Link: https://github.com/acpica/acpica/pull/786
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214899
Reported-and-tested-by: Johannes Penßel &lt;johannespenssel@posteo.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: processor: Fix previous acpi_processor_errata_piix4() fix</title>
<updated>2026-03-25T10:03:22+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2026-03-17T20:39:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=2e369ba9eb7b8a06e9cc35a3e7fe73e59272f8c2'/>
<id>2e369ba9eb7b8a06e9cc35a3e7fe73e59272f8c2</id>
<content type='text'>
[ Upstream commit bf504b229cb8d534eccbaeaa23eba34c05131e25 ]

After commi f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference
in acpi_processor_errata_piix4()"), device pointers may be dereferenced
after dropping references to the device objects pointed to by them,
which may cause a use-after-free to occur.

Moreover, debug messages about enabling the errata may be printed
if the errata flags corresponding to them are unset.

Address all of these issues by moving message printing to the points
in the code where the errata flags are set.

Fixes: f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()")
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Closes: https://lore.kernel.org/linux-acpi/938e2206-def5-4b7a-9b2c-d1fd37681d8a@roeck-us.net/
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/5975693.DvuYhMxLoT@rafael.j.wysocki
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bf504b229cb8d534eccbaeaa23eba34c05131e25 ]

After commi f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference
in acpi_processor_errata_piix4()"), device pointers may be dereferenced
after dropping references to the device objects pointed to by them,
which may cause a use-after-free to occur.

Moreover, debug messages about enabling the errata may be printed
if the errata flags corresponding to them are unset.

Address all of these issues by moving message printing to the points
in the code where the errata flags are set.

Fixes: f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()")
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Closes: https://lore.kernel.org/linux-acpi/938e2206-def5-4b7a-9b2c-d1fd37681d8a@roeck-us.net/
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/5975693.DvuYhMxLoT@rafael.j.wysocki
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: OSL: fix __iomem type on return from acpi_os_map_generic_address()</title>
<updated>2026-03-25T10:03:05+00:00</updated>
<author>
<name>Ben Dooks</name>
<email>ben.dooks@codethink.co.uk</email>
</author>
<published>2026-03-11T10:58:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ef15faaa5d7b3005b5cc73ce20a111272a2697b0'/>
<id>ef15faaa5d7b3005b5cc73ce20a111272a2697b0</id>
<content type='text'>
[ Upstream commit 393815f57651101f1590632092986d1d5a3a41bd ]

The pointer returned from acpi_os_map_generic_address() is
tagged with __iomem, so make the rv it is returned to also
of void __iomem * type.

Fixes the following sparse warning:

drivers/acpi/osl.c:1686:20: warning: incorrect type in assignment (different address spaces)
drivers/acpi/osl.c:1686:20:    expected void *rv
drivers/acpi/osl.c:1686:20:    got void [noderef] __iomem *

Fixes: 6915564dc5a8 ("ACPI: OSL: Change the type of acpi_os_map_generic_address() return value")
Signed-off-by: Ben Dooks &lt;ben.dooks@codethink.co.uk&gt;
[ rjw: Subject tweak, added Fixes tag ]
Link: https://patch.msgid.link/20260311105835.463030-1-ben.dooks@codethink.co.uk
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 393815f57651101f1590632092986d1d5a3a41bd ]

The pointer returned from acpi_os_map_generic_address() is
tagged with __iomem, so make the rv it is returned to also
of void __iomem * type.

Fixes the following sparse warning:

drivers/acpi/osl.c:1686:20: warning: incorrect type in assignment (different address spaces)
drivers/acpi/osl.c:1686:20:    expected void *rv
drivers/acpi/osl.c:1686:20:    got void [noderef] __iomem *

Fixes: 6915564dc5a8 ("ACPI: OSL: Change the type of acpi_os_map_generic_address() return value")
Signed-off-by: Ben Dooks &lt;ben.dooks@codethink.co.uk&gt;
[ rjw: Subject tweak, added Fixes tag ]
Link: https://patch.msgid.link/20260311105835.463030-1-ben.dooks@codethink.co.uk
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: OSI: Add DMI quirk for Acer Aspire One D255</title>
<updated>2026-03-25T10:03:03+00:00</updated>
<author>
<name>Sofia Schneider</name>
<email>sofia@schn.dev</email>
</author>
<published>2026-02-23T02:52:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=416f4a7bde7143b96fc7fba9b6706ab8a64e06dd'/>
<id>416f4a7bde7143b96fc7fba9b6706ab8a64e06dd</id>
<content type='text'>
[ Upstream commit 5ede90206273ff156a778254f0f972a55e973c89 ]

The screen backlight turns off during boot (specifically during udev device
initialization) when returning true for _OSI("Windows 2009").

Analyzing the device's DSDT reveals that the firmware takes a different
code path when Windows 7 is reported, which leads to the backlight shutoff.
Add a DMI quirk to invoke dmi_disable_osi_win7 for this model.

Signed-off-by: Sofia Schneider &lt;sofia@schn.dev&gt;
Link: https://patch.msgid.link/20260223025240.518509-1-sofia@schn.dev
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5ede90206273ff156a778254f0f972a55e973c89 ]

The screen backlight turns off during boot (specifically during udev device
initialization) when returning true for _OSI("Windows 2009").

Analyzing the device's DSDT reveals that the firmware takes a different
code path when Windows 7 is reported, which leads to the backlight shutoff.
Add a DMI quirk to invoke dmi_disable_osi_win7 for this model.

Signed-off-by: Sofia Schneider &lt;sofia@schn.dev&gt;
Link: https://patch.msgid.link/20260223025240.518509-1-sofia@schn.dev
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: PM: Save NVS memory on Lenovo G70-35</title>
<updated>2026-03-25T10:03:02+00:00</updated>
<author>
<name>Piotr Mazek</name>
<email>pmazek@outlook.com</email>
</author>
<published>2026-02-05T22:05:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=2303cbea15725c56c5ab98baf0d964861c449620'/>
<id>2303cbea15725c56c5ab98baf0d964861c449620</id>
<content type='text'>
[ Upstream commit 023cd6d90f8aa2ef7b72d84be84a18e61ecebd64 ]

[821d6f0359b0614792ab8e2fb93b503e25a65079] prevented machines
produced later than 2012 from saving NVS region to accelerate S3.

Despite being made after 2012, Lenovo G70-35 still needs NVS memory
saving during S3. A quirk is introduced for this platform.

Signed-off-by: Piotr Mazek &lt;pmazek@outlook.com&gt;
[ rjw: Subject adjustment ]
Link: https://patch.msgid.link/GV2PPF3CD5B63CC2442EE3F76F8443EAD90D499A@GV2PPF3CD5B63CC.EURP251.PROD.OUTLOOK.COM
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 023cd6d90f8aa2ef7b72d84be84a18e61ecebd64 ]

[821d6f0359b0614792ab8e2fb93b503e25a65079] prevented machines
produced later than 2012 from saving NVS region to accelerate S3.

Despite being made after 2012, Lenovo G70-35 still needs NVS memory
saving during S3. A quirk is introduced for this platform.

Signed-off-by: Piotr Mazek &lt;pmazek@outlook.com&gt;
[ rjw: Subject adjustment ]
Link: https://patch.msgid.link/GV2PPF3CD5B63CC2442EE3F76F8443EAD90D499A@GV2PPF3CD5B63CC.EURP251.PROD.OUTLOOK.COM
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
