<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/base/power, branch linux-5.6.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>PM: sleep: core: Switch back to async_schedule_dev()</title>
<updated>2020-05-02T06:50:53+00:00</updated>
<author>
<name>Kai-Heng Feng</name>
<email>kai.heng.feng@canonical.com</email>
</author>
<published>2020-04-21T08:21:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=be554983e707523a89c0c50761c36a80ecca2446'/>
<id>be554983e707523a89c0c50761c36a80ecca2446</id>
<content type='text'>
commit 09beebd8f93b3c8bf894e342f0a203a5c612478c upstream.

Commit 8b9ec6b73277 ("PM core: Use new async_schedule_dev command")
introduced a new function for better performance.

However commit f2a424f6c613 ("PM / core: Introduce dpm_async_fn()
helper") went back to the non-optimized version, async_schedule().

So switch back to the sync_schedule_dev() to improve performance

Fixes: f2a424f6c613 ("PM / core: Introduce dpm_async_fn() helper")
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.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 09beebd8f93b3c8bf894e342f0a203a5c612478c upstream.

Commit 8b9ec6b73277 ("PM core: Use new async_schedule_dev command")
introduced a new function for better performance.

However commit f2a424f6c613 ("PM / core: Introduce dpm_async_fn()
helper") went back to the non-optimized version, async_schedule().

So switch back to the sync_schedule_dev() to improve performance

Fixes: f2a424f6c613 ("PM / core: Introduce dpm_async_fn() helper")
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.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>PM: sleep: wakeup: Skip wakeup_source_sysfs_remove() if device is not there</title>
<updated>2020-04-17T14:13:31+00:00</updated>
<author>
<name>Neeraj Upadhyay</name>
<email>neeraju@codeaurora.org</email>
</author>
<published>2020-03-23T05:08:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0047e343b2229e1737b454bb058343d464e9cff6'/>
<id>0047e343b2229e1737b454bb058343d464e9cff6</id>
<content type='text'>
commit 87de6594dc45dbf6819f3e0ef92f9331c5a9444c upstream.

Skip wakeup_source_sysfs_remove() to fix a NULL pinter dereference via
ws-&gt;dev, if the wakeup source is unregistered before registering the
wakeup class from device_add().

Fixes: 2ca3d1ecb8c4 ("PM / wakeup: Register wakeup class kobj after device is added")
Signed-off-by: Neeraj Upadhyay &lt;neeraju@codeaurora.org&gt;
Cc: 5.4+ &lt;stable@vger.kernel.org&gt; # 5.4+
[ rjw: Subject &amp; changelog, white space ]
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 87de6594dc45dbf6819f3e0ef92f9331c5a9444c upstream.

Skip wakeup_source_sysfs_remove() to fix a NULL pinter dereference via
ws-&gt;dev, if the wakeup source is unregistered before registering the
wakeup class from device_add().

Fixes: 2ca3d1ecb8c4 ("PM / wakeup: Register wakeup class kobj after device is added")
Signed-off-by: Neeraj Upadhyay &lt;neeraju@codeaurora.org&gt;
Cc: 5.4+ &lt;stable@vger.kernel.org&gt; # 5.4+
[ rjw: Subject &amp; changelog, white space ]
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>PM / Domains: Allow no domain-idle-states DT property in genpd when parsing</title>
<updated>2020-04-17T14:13:31+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2020-03-10T10:40:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1a377e65564f0a2718f8da12e7e790d236fb9166'/>
<id>1a377e65564f0a2718f8da12e7e790d236fb9166</id>
<content type='text'>
commit 56cb26891ea4180121265dc6b596015772c4a4b8 upstream.

Commit 2c361684803e ("PM / Domains: Don't treat zero found compatible idle
states as an error"), moved of_genpd_parse_idle_states() towards allowing
none compatible idle state to be found for the device node, rather than
returning an error code.

However, it didn't consider that the "domain-idle-states" DT property may
be missing as it's optional, which makes of_count_phandle_with_args() to
return -ENOENT. Let's fix this to make the behaviour consistent.

Fixes: 2c361684803e ("PM / Domains: Don't treat zero found compatible idle states as an error")
Reported-by: Benjamin Gaignard &lt;benjamin.gaignard@st.com&gt;
Cc: 4.20+ &lt;stable@vger.kernel.org&gt; # 4.20+
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.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 56cb26891ea4180121265dc6b596015772c4a4b8 upstream.

Commit 2c361684803e ("PM / Domains: Don't treat zero found compatible idle
states as an error"), moved of_genpd_parse_idle_states() towards allowing
none compatible idle state to be found for the device node, rather than
returning an error code.

However, it didn't consider that the "domain-idle-states" DT property may
be missing as it's optional, which makes of_count_phandle_with_args() to
return -ENOENT. Let's fix this to make the behaviour consistent.

Fixes: 2c361684803e ("PM / Domains: Don't treat zero found compatible idle states as an error")
Reported-by: Benjamin Gaignard &lt;benjamin.gaignard@st.com&gt;
Cc: 4.20+ &lt;stable@vger.kernel.org&gt; # 4.20+
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.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>Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc</title>
<updated>2020-02-08T22:04:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-02-08T22:04:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eab3540562fb44f830e09492374fcc69a283ce47'/>
<id>eab3540562fb44f830e09492374fcc69a283ce47</id>
<content type='text'>
Pull ARM SoC-related driver updates from Olof Johansson:
 "Various driver updates for platforms:

   - Nvidia: Fuse support for Tegra194, continued memory controller
     pieces for Tegra30

   - NXP/FSL: Refactorings of QuickEngine drivers to support
     ARM/ARM64/PPC

   - NXP/FSL: i.MX8MP SoC driver pieces

   - TI Keystone: ring accelerator driver

   - Qualcomm: SCM driver cleanup/refactoring + support for new SoCs.

   - Xilinx ZynqMP: feature checking interface for firmware. Mailbox
     communication for power management

   - Overall support patch set for cpuidle on more complex hierarchies
     (PSCI-based)

  and misc cleanups, refactorings of Marvell, TI, other platforms"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (166 commits)
  drivers: soc: xilinx: Use mailbox IPI callback
  dt-bindings: power: reset: xilinx: Add bindings for ipi mailbox
  drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists
  MAINTAINERS: Add brcmstb PCIe controller entry
  soc/tegra: fuse: Unmap registers once they are not needed anymore
  soc/tegra: fuse: Correct straps' address for older Tegra124 device trees
  soc/tegra: fuse: Warn if straps are not ready
  soc/tegra: fuse: Cache values of straps and Chip ID registers
  memory: tegra30-emc: Correct error message for timed out auto calibration
  memory: tegra30-emc: Firm up hardware programming sequence
  memory: tegra30-emc: Firm up suspend/resume sequence
  soc/tegra: regulators: Do nothing if voltage is unchanged
  memory: tegra: Correct reset value of xusb_hostr
  soc/tegra: fuse: Add APB DMA dependency for Tegra20
  bus: tegra-aconnect: Remove PM_CLK dependency
  dt-bindings: mediatek: add MT6765 power dt-bindings
  soc: mediatek: cmdq: delete not used define
  memory: tegra: Add support for the Tegra194 memory controller
  memory: tegra: Only include support for enabled SoCs
  memory: tegra: Support DVFS on Tegra186 and later
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ARM SoC-related driver updates from Olof Johansson:
 "Various driver updates for platforms:

   - Nvidia: Fuse support for Tegra194, continued memory controller
     pieces for Tegra30

   - NXP/FSL: Refactorings of QuickEngine drivers to support
     ARM/ARM64/PPC

   - NXP/FSL: i.MX8MP SoC driver pieces

   - TI Keystone: ring accelerator driver

   - Qualcomm: SCM driver cleanup/refactoring + support for new SoCs.

   - Xilinx ZynqMP: feature checking interface for firmware. Mailbox
     communication for power management

   - Overall support patch set for cpuidle on more complex hierarchies
     (PSCI-based)

  and misc cleanups, refactorings of Marvell, TI, other platforms"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (166 commits)
  drivers: soc: xilinx: Use mailbox IPI callback
  dt-bindings: power: reset: xilinx: Add bindings for ipi mailbox
  drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists
  MAINTAINERS: Add brcmstb PCIe controller entry
  soc/tegra: fuse: Unmap registers once they are not needed anymore
  soc/tegra: fuse: Correct straps' address for older Tegra124 device trees
  soc/tegra: fuse: Warn if straps are not ready
  soc/tegra: fuse: Cache values of straps and Chip ID registers
  memory: tegra30-emc: Correct error message for timed out auto calibration
  memory: tegra30-emc: Firm up hardware programming sequence
  memory: tegra30-emc: Firm up suspend/resume sequence
  soc/tegra: regulators: Do nothing if voltage is unchanged
  memory: tegra: Correct reset value of xusb_hostr
  soc/tegra: fuse: Add APB DMA dependency for Tegra20
  bus: tegra-aconnect: Remove PM_CLK dependency
  dt-bindings: mediatek: add MT6765 power dt-bindings
  soc: mediatek: cmdq: delete not used define
  memory: tegra: Add support for the Tegra194 memory controller
  memory: tegra: Only include support for enabled SoCs
  memory: tegra: Support DVFS on Tegra186 and later
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pm-5.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2020-01-31T22:36:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-01-31T22:36:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cf3c8f84d1401fed5010784034d104cc689061d5'/>
<id>cf3c8f84d1401fed5010784034d104cc689061d5</id>
<content type='text'>
Pull more power manadement updates from Rafael Wysocki:
 "Prevent cpufreq from creating excessively large stack frames and fix
  the handling of devices deleted during system-wide resume in the PM
  core (Rafael Wysocki), revert a problematic commit affecting the
  cpupower utility and correct its man page (Thomas Renninger,
  Brahadambal Srinivasan), and improve the intel_pstate_tracer utility
  (Doug Smythies)"

* tag 'pm-5.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  tools/power/x86/intel_pstate_tracer: change several graphs to autoscale y-axis
  tools/power/x86/intel_pstate_tracer: changes for python 3 compatibility
  Correction to manpage of cpupower
  cpufreq: Avoid creating excessively large stack frames
  PM: core: Fix handling of devices deleted during system-wide resume
  cpupower: Revert library ABI changes from commit ae2917093fb60bdc1ed3e
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more power manadement updates from Rafael Wysocki:
 "Prevent cpufreq from creating excessively large stack frames and fix
  the handling of devices deleted during system-wide resume in the PM
  core (Rafael Wysocki), revert a problematic commit affecting the
  cpupower utility and correct its man page (Thomas Renninger,
  Brahadambal Srinivasan), and improve the intel_pstate_tracer utility
  (Doug Smythies)"

* tag 'pm-5.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  tools/power/x86/intel_pstate_tracer: change several graphs to autoscale y-axis
  tools/power/x86/intel_pstate_tracer: changes for python 3 compatibility
  Correction to manpage of cpupower
  cpufreq: Avoid creating excessively large stack frames
  PM: core: Fix handling of devices deleted during system-wide resume
  cpupower: Revert library ABI changes from commit ae2917093fb60bdc1ed3e
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'pm-cpufreq' and 'pm-core'</title>
<updated>2020-01-31T09:28:23+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2020-01-31T09:28:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=82b2c6ffd399c9fcd542fd681bb8c6d41f035c7e'/>
<id>82b2c6ffd399c9fcd542fd681bb8c6d41f035c7e</id>
<content type='text'>
* pm-cpufreq:
  cpufreq: Avoid creating excessively large stack frames

* pm-core:
  PM: core: Fix handling of devices deleted during system-wide resume
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-cpufreq:
  cpufreq: Avoid creating excessively large stack frames

* pm-core:
  PM: core: Fix handling of devices deleted during system-wide resume
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest</title>
<updated>2020-01-29T23:25:34+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-01-29T23:25:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=08a3ef8f6b0b1341c670caba35f782c9a452d488'/>
<id>08a3ef8f6b0b1341c670caba35f782c9a452d488</id>
<content type='text'>
Pull Kselftest kunit updates from Shuah Khan:
 "This kunit update consists of:

   - Support for building kunit as a module from Alan Maguire

   - AppArmor KUnit tests for policy unpack from Mike Salvatore"

* tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: building kunit as a module breaks allmodconfig
  kunit: update documentation to describe module-based build
  kunit: allow kunit to be loaded as a module
  kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds
  kunit: allow kunit tests to be loaded as a module
  kunit: hide unexported try-catch interface in try-catch-impl.h
  kunit: move string-stream.h to lib/kunit
  apparmor: add AppArmor KUnit tests for policy unpack
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kselftest kunit updates from Shuah Khan:
 "This kunit update consists of:

   - Support for building kunit as a module from Alan Maguire

   - AppArmor KUnit tests for policy unpack from Mike Salvatore"

* tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: building kunit as a module breaks allmodconfig
  kunit: update documentation to describe module-based build
  kunit: allow kunit to be loaded as a module
  kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds
  kunit: allow kunit tests to be loaded as a module
  kunit: hide unexported try-catch interface in try-catch-impl.h
  kunit: move string-stream.h to lib/kunit
  apparmor: add AppArmor KUnit tests for policy unpack
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'pm-core', 'powercap', 'pm-opp', 'pm-avs' and 'pm-misc'</title>
<updated>2020-01-27T10:30:13+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2020-01-27T10:30:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c95d9c140cea04bb052bd853eee24d0020734d9d'/>
<id>c95d9c140cea04bb052bd853eee24d0020734d9d</id>
<content type='text'>
* pm-core:
  PM-runtime: add tracepoints for usage_count changes

* powercap:
  powercap/intel_rapl: add support for JasperLake
  x86/cpu: Add Jasper Lake to Intel family
  powercap/intel_rapl: add support for TigerLake Mobile

* pm-opp:
  opp: Replace list_kref with a local counter
  opp: Free static OPPs on errors while adding them

* pm-avs:
  power: avs: qcom-cpr: remove duplicated include from qcom-cpr.c
  power: avs: fix uninitialized error return on failed cpr_read_fuse_uV() call
  power: avs: qcom-cpr: make cpr_get_opp_hz_for_req() static
  power: avs: qcom-cpr: remove set but unused variable
  power: avs: qcom-cpr: make sure that regmap is available
  power: avs: qcom-cpr: fix unsigned expression compared with zero
  power: avs: qcom-cpr: fix invalid printk specifier in debug print
  power: avs: Add support for CPR (Core Power Reduction)
  dt-bindings: power: avs: Add support for CPR (Core Power Reduction)

* pm-misc:
  mailmap: Add entry for &lt;rjw@sisk.pl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-core:
  PM-runtime: add tracepoints for usage_count changes

* powercap:
  powercap/intel_rapl: add support for JasperLake
  x86/cpu: Add Jasper Lake to Intel family
  powercap/intel_rapl: add support for TigerLake Mobile

* pm-opp:
  opp: Replace list_kref with a local counter
  opp: Free static OPPs on errors while adding them

* pm-avs:
  power: avs: qcom-cpr: remove duplicated include from qcom-cpr.c
  power: avs: fix uninitialized error return on failed cpr_read_fuse_uV() call
  power: avs: qcom-cpr: make cpr_get_opp_hz_for_req() static
  power: avs: qcom-cpr: remove set but unused variable
  power: avs: qcom-cpr: make sure that regmap is available
  power: avs: qcom-cpr: fix unsigned expression compared with zero
  power: avs: qcom-cpr: fix invalid printk specifier in debug print
  power: avs: Add support for CPR (Core Power Reduction)
  dt-bindings: power: avs: Add support for CPR (Core Power Reduction)

* pm-misc:
  mailmap: Add entry for &lt;rjw@sisk.pl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: core: Fix handling of devices deleted during system-wide resume</title>
<updated>2020-01-24T13:27:05+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2020-01-22T23:11:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0552e05fdfea191a2cf3a0abd33574b5ef9ca818'/>
<id>0552e05fdfea191a2cf3a0abd33574b5ef9ca818</id>
<content type='text'>
If a device is deleted by one of its system-wide resume callbacks
(for example, because it does not appear to be present or accessible
any more) along with its children, the resume of the children may
continue leading to use-after-free errors and other issues
(potentially).

Namely, if the device's children are resumed asynchronously, their
resume may have been scheduled already before the device's callback
runs and so the device may be deleted while dpm_wait_for_superior()
is being executed for them.  The memory taken up by the parent device
object may be freed then while dpm_wait() is waiting for the parent's
resume callback to complete, which leads to a use-after-free.
Moreover, the resume of the children is really not expected to
continue after they have been unregistered, so it must be terminated
right away in that case.

To address this problem, modify dpm_wait_for_superior() to check
if the target device is still there in the system-wide PM list of
devices and if so, to increment its parent's reference counter, both
under dpm_list_mtx which prevents device_del() running for the child
from dropping the parent's reference counter prematurely.

If the device is not present in the system-wide PM list of devices
any more, the resume of it cannot continue, so check that again after
dpm_wait() returns, which means that the parent's callback has been
completed, and pass the result of that check to the caller of
dpm_wait_for_superior() to allow it to abort the device's resume
if it is not there any more.

Link: https://lore.kernel.org/linux-pm/1579568452-27253-1-git-send-email-chanho.min@lge.com
Reported-by: Chanho Min &lt;chanho.min@lge.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If a device is deleted by one of its system-wide resume callbacks
(for example, because it does not appear to be present or accessible
any more) along with its children, the resume of the children may
continue leading to use-after-free errors and other issues
(potentially).

Namely, if the device's children are resumed asynchronously, their
resume may have been scheduled already before the device's callback
runs and so the device may be deleted while dpm_wait_for_superior()
is being executed for them.  The memory taken up by the parent device
object may be freed then while dpm_wait() is waiting for the parent's
resume callback to complete, which leads to a use-after-free.
Moreover, the resume of the children is really not expected to
continue after they have been unregistered, so it must be terminated
right away in that case.

To address this problem, modify dpm_wait_for_superior() to check
if the target device is still there in the system-wide PM list of
devices and if so, to increment its parent's reference counter, both
under dpm_list_mtx which prevents device_del() running for the child
from dropping the parent's reference counter prematurely.

If the device is not present in the system-wide PM list of devices
any more, the resume of it cannot continue, so check that again after
dpm_wait() returns, which means that the parent's callback has been
completed, and pass the result of that check to the caller of
dpm_wait_for_superior() to allow it to abort the device's resume
if it is not there any more.

Link: https://lore.kernel.org/linux-pm/1579568452-27253-1-git-send-email-chanho.min@lge.com
Reported-by: Chanho Min &lt;chanho.min@lge.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM-runtime: add tracepoints for usage_count changes</title>
<updated>2020-01-13T11:28:29+00:00</updated>
<author>
<name>Michał Mirosław</name>
<email>mirq-linux@rere.qmqm.pl</email>
</author>
<published>2020-01-04T16:27:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d229290689ae0f6eae068ef142de4fd61ab4ba50'/>
<id>d229290689ae0f6eae068ef142de4fd61ab4ba50</id>
<content type='text'>
Add tracepoints to remaining places where device's power.usage_count
is changed.

This helps debugging where and why autosuspend is prevented.

Signed-off-by: Michał Mirosław &lt;mirq-linux@rere.qmqm.pl&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>
Add tracepoints to remaining places where device's power.usage_count
is changed.

This helps debugging where and why autosuspend is prevented.

Signed-off-by: Michał Mirosław &lt;mirq-linux@rere.qmqm.pl&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
