<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/acpi, branch v4.4.210</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ACPI: PM: Avoid attaching ACPI PM domain to certain devices</title>
<updated>2019-12-21T09:35:28+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-12-04T01:54:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d59b991b48acddb528472f0d4467514c86cef26d'/>
<id>d59b991b48acddb528472f0d4467514c86cef26d</id>
<content type='text'>
commit b9ea0bae260f6aae546db224daa6ac1bd9d94b91 upstream.

Certain ACPI-enumerated devices represented as platform devices in
Linux, like fans, require special low-level power management handling
implemented by their drivers that is not in agreement with the ACPI
PM domain behavior.  That leads to problems with managing ACPI fans
during system-wide suspend and resume.

For this reason, make acpi_dev_pm_attach() skip the affected devices
by adding a list of device IDs to avoid to it and putting the IDs of
the affected devices into that list.

Fixes: e5cc8ef31267 (ACPI / PM: Provide ACPI PM callback routines for subsystems)
Reported-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Todd Brandt &lt;todd.e.brandt@linux.intel.com&gt;
Cc: 3.10+ &lt;stable@vger.kernel.org&gt; # 3.10+
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 b9ea0bae260f6aae546db224daa6ac1bd9d94b91 upstream.

Certain ACPI-enumerated devices represented as platform devices in
Linux, like fans, require special low-level power management handling
implemented by their drivers that is not in agreement with the ACPI
PM domain behavior.  That leads to problems with managing ACPI fans
during system-wide suspend and resume.

For this reason, make acpi_dev_pm_attach() skip the affected devices
by adding a list of device IDs to avoid to it and putting the IDs of
the affected devices into that list.

Fixes: e5cc8ef31267 (ACPI / PM: Provide ACPI PM callback routines for subsystems)
Reported-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Todd Brandt &lt;todd.e.brandt@linux.intel.com&gt;
Cc: 3.10+ &lt;stable@vger.kernel.org&gt; # 3.10+
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: bus: Fix NULL pointer check in acpi_bus_get_private_data()</title>
<updated>2019-12-21T09:35:28+00:00</updated>
<author>
<name>Vamshi K Sthambamkadi</name>
<email>vamshi.k.sthambamkadi@gmail.com</email>
</author>
<published>2019-11-28T10:28:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=45e64c927533394ff9427a93587998859c0fd77a'/>
<id>45e64c927533394ff9427a93587998859c0fd77a</id>
<content type='text'>
commit 627ead724eff33673597216f5020b72118827de4 upstream.

kmemleak reported backtrace:
    [&lt;bbee0454&gt;] kmem_cache_alloc_trace+0x128/0x260
    [&lt;6677f215&gt;] i2c_acpi_install_space_handler+0x4b/0xe0
    [&lt;1180f4fc&gt;] i2c_register_adapter+0x186/0x400
    [&lt;6083baf7&gt;] i2c_add_adapter+0x4e/0x70
    [&lt;a3ddf966&gt;] intel_gmbus_setup+0x1a2/0x2c0 [i915]
    [&lt;84cb69ae&gt;] i915_driver_probe+0x8d8/0x13a0 [i915]
    [&lt;81911d4b&gt;] i915_pci_probe+0x48/0x160 [i915]
    [&lt;4b159af1&gt;] pci_device_probe+0xdc/0x160
    [&lt;b3c64704&gt;] really_probe+0x1ee/0x450
    [&lt;bc029f5a&gt;] driver_probe_device+0x142/0x1b0
    [&lt;d8829d20&gt;] device_driver_attach+0x49/0x50
    [&lt;de71f045&gt;] __driver_attach+0xc9/0x150
    [&lt;df33ac83&gt;] bus_for_each_dev+0x56/0xa0
    [&lt;80089bba&gt;] driver_attach+0x19/0x20
    [&lt;cc73f583&gt;] bus_add_driver+0x177/0x220
    [&lt;7b29d8c7&gt;] driver_register+0x56/0xf0

In i2c_acpi_remove_space_handler(), a leak occurs whenever the
"data" parameter is initialized to 0 before being passed to
acpi_bus_get_private_data().

This is because the NULL pointer check in acpi_bus_get_private_data()
(condition-&gt;if(!*data)) returns EINVAL and, in consequence, memory is
never freed in i2c_acpi_remove_space_handler().

Fix the NULL pointer check in acpi_bus_get_private_data() to follow
the analogous check in acpi_get_data_full().

Signed-off-by: Vamshi K Sthambamkadi &lt;vamshi.k.sthambamkadi@gmail.com&gt;
[ rjw: Subject &amp; changelog ]
Cc: All applicable &lt;stable@vger.kernel.org&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 627ead724eff33673597216f5020b72118827de4 upstream.

kmemleak reported backtrace:
    [&lt;bbee0454&gt;] kmem_cache_alloc_trace+0x128/0x260
    [&lt;6677f215&gt;] i2c_acpi_install_space_handler+0x4b/0xe0
    [&lt;1180f4fc&gt;] i2c_register_adapter+0x186/0x400
    [&lt;6083baf7&gt;] i2c_add_adapter+0x4e/0x70
    [&lt;a3ddf966&gt;] intel_gmbus_setup+0x1a2/0x2c0 [i915]
    [&lt;84cb69ae&gt;] i915_driver_probe+0x8d8/0x13a0 [i915]
    [&lt;81911d4b&gt;] i915_pci_probe+0x48/0x160 [i915]
    [&lt;4b159af1&gt;] pci_device_probe+0xdc/0x160
    [&lt;b3c64704&gt;] really_probe+0x1ee/0x450
    [&lt;bc029f5a&gt;] driver_probe_device+0x142/0x1b0
    [&lt;d8829d20&gt;] device_driver_attach+0x49/0x50
    [&lt;de71f045&gt;] __driver_attach+0xc9/0x150
    [&lt;df33ac83&gt;] bus_for_each_dev+0x56/0xa0
    [&lt;80089bba&gt;] driver_attach+0x19/0x20
    [&lt;cc73f583&gt;] bus_add_driver+0x177/0x220
    [&lt;7b29d8c7&gt;] driver_register+0x56/0xf0

In i2c_acpi_remove_space_handler(), a leak occurs whenever the
"data" parameter is initialized to 0 before being passed to
acpi_bus_get_private_data().

This is because the NULL pointer check in acpi_bus_get_private_data()
(condition-&gt;if(!*data)) returns EINVAL and, in consequence, memory is
never freed in i2c_acpi_remove_space_handler().

Fix the NULL pointer check in acpi_bus_get_private_data() to follow
the analogous check in acpi_get_data_full().

Signed-off-by: Vamshi K Sthambamkadi &lt;vamshi.k.sthambamkadi@gmail.com&gt;
[ rjw: Subject &amp; changelog ]
Cc: All applicable &lt;stable@vger.kernel.org&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: OSL: only free map once in osl.c</title>
<updated>2019-12-21T09:35:27+00:00</updated>
<author>
<name>Francesco Ruggeri</name>
<email>fruggeri@arista.com</email>
</author>
<published>2019-11-20T05:47:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6fb1c89b1e69c94fae74a5add7e9be123914545d'/>
<id>6fb1c89b1e69c94fae74a5add7e9be123914545d</id>
<content type='text'>
commit 833a426cc471b6088011b3d67f1dc4e147614647 upstream.

acpi_os_map_cleanup checks map-&gt;refcount outside of acpi_ioremap_lock
before freeing the map. This creates a race condition the can result
in the map being freed more than once.
A panic can be caused by running

for ((i=0; i&lt;10; i++))
do
        for ((j=0; j&lt;100000; j++))
        do
                cat /sys/firmware/acpi/tables/data/BERT &gt;/dev/null
        done &amp;
done

This patch makes sure that only the process that drops the reference
to 0 does the freeing.

Fixes: b7c1fadd6c2e ("ACPI: Do not use krefs under a mutex in osl.c")
Signed-off-by: Francesco Ruggeri &lt;fruggeri@arista.com&gt;
Reviewed-by: Dmitry Safonov &lt;0x7f454c46@gmail.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&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 833a426cc471b6088011b3d67f1dc4e147614647 upstream.

acpi_os_map_cleanup checks map-&gt;refcount outside of acpi_ioremap_lock
before freeing the map. This creates a race condition the can result
in the map being freed more than once.
A panic can be caused by running

for ((i=0; i&lt;10; i++))
do
        for ((j=0; j&lt;100000; j++))
        do
                cat /sys/firmware/acpi/tables/data/BERT &gt;/dev/null
        done &amp;
done

This patch makes sure that only the process that drops the reference
to 0 does the freeing.

Fixes: b7c1fadd6c2e ("ACPI: Do not use krefs under a mutex in osl.c")
Signed-off-by: Francesco Ruggeri &lt;fruggeri@arista.com&gt;
Reviewed-by: Dmitry Safonov &lt;0x7f454c46@gmail.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&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 / APEI: Switch estatus pool to use vmalloc memory</title>
<updated>2019-12-05T14:27:09+00:00</updated>
<author>
<name>James Morse</name>
<email>james.morse@arm.com</email>
</author>
<published>2019-01-29T18:48:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5b16614297970daad30328246c7b6611699552d0'/>
<id>5b16614297970daad30328246c7b6611699552d0</id>
<content type='text'>
[ Upstream commit 0ac234be1a9497498e57d958f4251f5257b116b4 ]

The ghes code is careful to parse and round firmware's advertised
memory requirements for CPER records, up to a maximum of 64K.
However when ghes_estatus_pool_expand() does its work, it splits
the requested size into PAGE_SIZE granules.

This means if firmware generates 5K of CPER records, and correctly
describes this in the table, __process_error() will silently fail as it
is unable to allocate more than PAGE_SIZE.

Switch the estatus pool to vmalloc() memory. On x86 vmalloc() memory
may fault and be fixed up by vmalloc_fault(). To prevent this call
vmalloc_sync_all() before an NMI handler could discover the memory.

Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Reviewed-by: Borislav Petkov &lt;bp@suse.de&gt;
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 0ac234be1a9497498e57d958f4251f5257b116b4 ]

The ghes code is careful to parse and round firmware's advertised
memory requirements for CPER records, up to a maximum of 64K.
However when ghes_estatus_pool_expand() does its work, it splits
the requested size into PAGE_SIZE granules.

This means if firmware generates 5K of CPER records, and correctly
describes this in the table, __process_error() will silently fail as it
is unable to allocate more than PAGE_SIZE.

Switch the estatus pool to vmalloc() memory. On x86 vmalloc() memory
may fault and be fixed up by vmalloc_fault(). To prevent this call
vmalloc_sync_all() before an NMI handler could discover the memory.

Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Reviewed-by: Borislav Petkov &lt;bp@suse.de&gt;
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 / LPSS: Ignore acpi_device_fix_up_power() return value</title>
<updated>2019-12-05T14:26:41+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2018-12-08T12:59:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=54878c24f874c1624a40e871580b4aa35d8ba37d'/>
<id>54878c24f874c1624a40e871580b4aa35d8ba37d</id>
<content type='text'>
[ Upstream commit 1a2fa02f7489dc4d746f2a15fb77b3ce1affade8 ]

Ignore acpi_device_fix_up_power() return value. If we return an error
we end up with acpi_default_enumeration() still creating a platform-
device for the device and we end up with the device still being used
but without the special LPSS related handling which is not useful.

Specicifically ignoring the error fixes the touchscreen no longer
working after a suspend/resume on a Prowise PT301 tablet.

This tablet has a broken _PS0 method on the touchscreen's I2C controller,
causing acpi_device_fix_up_power() to fail, causing fallback to standard
platform-dev handling and specifically causing acpi_lpss_save/restore_ctx
to not run.

The I2C controllers _PS0 method does actually turn on the device, but then
does some more nonsense which fails when run during early boot trying to
use I2C opregion handling on another not-yet registered I2C controller.

Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
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 1a2fa02f7489dc4d746f2a15fb77b3ce1affade8 ]

Ignore acpi_device_fix_up_power() return value. If we return an error
we end up with acpi_default_enumeration() still creating a platform-
device for the device and we end up with the device still being used
but without the special LPSS related handling which is not useful.

Specicifically ignoring the error fixes the touchscreen no longer
working after a suspend/resume on a Prowise PT301 tablet.

This tablet has a broken _PS0 method on the touchscreen's I2C controller,
causing acpi_device_fix_up_power() to fail, causing fallback to standard
platform-dev handling and specifically causing acpi_lpss_save/restore_ctx
to not run.

The I2C controllers _PS0 method does actually turn on the device, but then
does some more nonsense which fails when run during early boot trying to
use I2C opregion handling on another not-yet registered I2C controller.

Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
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 / SBS: Fix rare oops when removing modules</title>
<updated>2019-11-25T14:54:46+00:00</updated>
<author>
<name>Ronald Tschalär</name>
<email>ronald@innovation.ch</email>
</author>
<published>2018-10-01T02:53:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=682e2ea0ca94e4cd8d244fd6c276ab3f6d9c51ab'/>
<id>682e2ea0ca94e4cd8d244fd6c276ab3f6d9c51ab</id>
<content type='text'>
[ Upstream commit 757c968c442397f1249bb775a7c8c03842e3e0c7 ]

There was a small race when removing the sbshc module where
smbus_alarm() had queued acpi_smbus_callback() for deferred execution
but it hadn't been run yet, so that when it did run hc had been freed
and the module unloaded, resulting in an invalid paging request.

A similar race existed when removing the sbs module with regards to
acpi_sbs_callback() (which is called from acpi_smbus_callback()).

We therefore need to ensure no callbacks are pending or executing before
the cleanups are done and the modules are removed.

Signed-off-by: Ronald TschalÃ¤r &lt;ronald@innovation.ch&gt;
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 757c968c442397f1249bb775a7c8c03842e3e0c7 ]

There was a small race when removing the sbshc module where
smbus_alarm() had queued acpi_smbus_callback() for deferred execution
but it hadn't been run yet, so that when it did run hc had been freed
and the module unloaded, resulting in an invalid paging request.

A similar race existed when removing the sbs module with regards to
acpi_sbs_callback() (which is called from acpi_smbus_callback()).

We therefore need to ensure no callbacks are pending or executing before
the cleanups are done and the modules are removed.

Signed-off-by: Ronald TschalÃ¤r &lt;ronald@innovation.ch&gt;
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>PCI/ACPI: Correct error message for ASPM disabling</title>
<updated>2019-11-25T14:54:00+00:00</updated>
<author>
<name>Sinan Kaya</name>
<email>okaya@kernel.org</email>
</author>
<published>2018-08-10T04:32:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f94cdf46eabb7dc408327ea99708873bbd4258cd'/>
<id>f94cdf46eabb7dc408327ea99708873bbd4258cd</id>
<content type='text'>
[ Upstream commit 1ad61b612b95980a4d970c52022aa01dfc0f6068 ]

If _OSC execution fails today for platforms without an _OSC entry, code is
printing a misleading message saying disabling ASPM as follows:

  acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM

We need to ensure that platform supports ASPM to begin with.

Reported-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Sinan Kaya &lt;okaya@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.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 1ad61b612b95980a4d970c52022aa01dfc0f6068 ]

If _OSC execution fails today for platforms without an _OSC entry, code is
printing a misleading message saying disabling ASPM as follows:

  acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM

We need to ensure that platform supports ASPM to begin with.

Reported-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Sinan Kaya &lt;okaya@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: custom_method: fix memory leaks</title>
<updated>2019-10-05T10:27:49+00:00</updated>
<author>
<name>Wenwen Wang</name>
<email>wenwen@cs.uga.edu</email>
</author>
<published>2019-08-16T05:08:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4bda2b79a9d04c8ba31681c66e95877dbb433416'/>
<id>4bda2b79a9d04c8ba31681c66e95877dbb433416</id>
<content type='text'>
[ Upstream commit 03d1571d9513369c17e6848476763ebbd10ec2cb ]

In cm_write(), 'buf' is allocated through kzalloc(). In the following
execution, if an error occurs, 'buf' is not deallocated, leading to memory
leaks. To fix this issue, free 'buf' before returning the error.

Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Wenwen Wang &lt;wenwen@cs.uga.edu&gt;
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 03d1571d9513369c17e6848476763ebbd10ec2cb ]

In cm_write(), 'buf' is allocated through kzalloc(). In the following
execution, if an error occurs, 'buf' is not deallocated, leading to memory
leaks. To fix this issue, free 'buf' before returning the error.

Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Wenwen Wang &lt;wenwen@cs.uga.edu&gt;
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 / CPPC: do not require the _PSD method</title>
<updated>2019-10-05T10:27:49+00:00</updated>
<author>
<name>Al Stone</name>
<email>ahs3@redhat.com</email>
</author>
<published>2019-08-28T00:21:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=318e486d4ed967187b91957d1683b8e75e2b1ea6'/>
<id>318e486d4ed967187b91957d1683b8e75e2b1ea6</id>
<content type='text'>
[ Upstream commit 4c4cdc4c63853fee48c02e25c8605fb65a6c9924 ]

According to the ACPI 6.3 specification, the _PSD method is optional
when using CPPC.  The underlying assumption is that each CPU can change
frequency independently from all other CPUs; _PSD is provided to tell
the OS that some processors can NOT do that.

However, the acpi_get_psd() function returns ENODEV if there is no _PSD
method present, or an ACPI error status if an error occurs when evaluating
_PSD, if present.  This makes _PSD mandatory when using CPPC, in violation
of the specification, and only on Linux.

This has forced some firmware writers to provide a dummy _PSD, even though
it is irrelevant, but only because Linux requires it; other OSPMs follow
the spec.  We really do not want to have OS specific ACPI tables, though.

So, correct acpi_get_psd() so that it does not return an error if there
is no _PSD method present, but does return a failure when the method can
not be executed properly.  This allows _PSD to be optional as it should
be.

Signed-off-by: Al Stone &lt;ahs3@redhat.com&gt;
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 4c4cdc4c63853fee48c02e25c8605fb65a6c9924 ]

According to the ACPI 6.3 specification, the _PSD method is optional
when using CPPC.  The underlying assumption is that each CPU can change
frequency independently from all other CPUs; _PSD is provided to tell
the OS that some processors can NOT do that.

However, the acpi_get_psd() function returns ENODEV if there is no _PSD
method present, or an ACPI error status if an error occurs when evaluating
_PSD, if present.  This makes _PSD mandatory when using CPPC, in violation
of the specification, and only on Linux.

This has forced some firmware writers to provide a dummy _PSD, even though
it is irrelevant, but only because Linux requires it; other OSPMs follow
the spec.  We really do not want to have OS specific ACPI tables, though.

So, correct acpi_get_psd() so that it does not return an error if there
is no _PSD method present, but does return a failure when the method can
not be executed properly.  This allows _PSD to be optional as it should
be.

Signed-off-by: Al Stone &lt;ahs3@redhat.com&gt;
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 / SBS: Fix GPE storm on recent MacBookPro's</title>
<updated>2019-04-27T07:33:58+00:00</updated>
<author>
<name>Ronald Tschalär</name>
<email>ronald@innovation.ch</email>
</author>
<published>2018-10-01T02:52:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c49c3925a8462a9804bf6e498af39378b619b095'/>
<id>c49c3925a8462a9804bf6e498af39378b619b095</id>
<content type='text'>
[ Upstream commit ca1721c5bee77105829cbd7baab8ee0eab85b06d ]

On Apple machines, plugging-in or unplugging the power triggers a GPE
for the EC. Since these machines expose an SBS device, this GPE ends
up triggering the acpi_sbs_callback(). This in turn tries to get the
status of the SBS charger. However, on MBP13,* and MBP14,* machines,
performing the smbus-read operation to get the charger's status triggers
the EC's GPE again. The result is an endless re-triggering and handling
of that GPE, consuming significant CPU resources (&gt; 50% in irq).

In the end this is quite similar to commit 3031cddea633 (ACPI / SBS:
Don't assume the existence of an SBS charger), except that on the above
machines a status of all 1's is returned. And like there, we just want
ignore the charger here.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198169
Signed-off-by: Ronald TschalÃ¤r &lt;ronald@innovation.ch&gt;
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 ca1721c5bee77105829cbd7baab8ee0eab85b06d ]

On Apple machines, plugging-in or unplugging the power triggers a GPE
for the EC. Since these machines expose an SBS device, this GPE ends
up triggering the acpi_sbs_callback(). This in turn tries to get the
status of the SBS charger. However, on MBP13,* and MBP14,* machines,
performing the smbus-read operation to get the charger's status triggers
the EC's GPE again. The result is an endless re-triggering and handling
of that GPE, consuming significant CPU resources (&gt; 50% in irq).

In the end this is quite similar to commit 3031cddea633 (ACPI / SBS:
Don't assume the existence of an SBS charger), except that on the above
machines a status of all 1's is returned. And like there, we just want
ignore the charger here.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198169
Signed-off-by: Ronald TschalÃ¤r &lt;ronald@innovation.ch&gt;
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>
