<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/base/power/runtime.c, branch linux-5.1.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2019-03-14T17:30:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-14T17:30:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9352ca585b2ac7b67d2119b9386573b2a4c0ef4b'/>
<id>9352ca585b2ac7b67d2119b9386573b2a4c0ef4b</id>
<content type='text'>
Pull more power management updates from Rafael Wysocki:
 "These are mostly fixes and cleanups on top of the previously merged
  power management material for 5.1-rc1 with one cpupower utility update
  that wasn't pushed earlier due to unfortunate timing.

  Specifics:

   - Fix registration of new cpuidle governors partially broken during
     the 5.0 development cycle by mistake (Rafael Wysocki).

   - Avoid integer overflows in the menu cpuidle governor by making it
     discard the overflowing data points upfront (Rafael Wysocki).

   - Fix minor mistake in the recent update of the iowait boost
     computation in the intel_pstate driver (Rafael Wysocki).

   - Drop incorrect __init annotation from one function in the pxa2xx
     cpufreq driver (Arnd Bergmann).

   - Fix the operating performance points (OPP) framework initialization
     for devices in multiple power domains if only one of them is
     scalable (Rajendra Nayak).

   - Fix mistake in dev_pm_opp_set_rate() which causes it to skip
     updating the performance state if the new frequency is the same as
     the old one (Viresh Kumar).

   - Rework the cancellation of wakeup source timers to avoid potential
     issues with it and do some cleanups unlocked by that change (Viresh
     Kumar, Rafael Wysocki).

   - Clean up the code computing the active/suspended time of devices in
     the PM-runtime framework after recent changes (Ulf Hansson).

   - Make the power management infrastructure code use pr_fmt()
     consistently (Joe Perches).

   - Clean up the generic power domains (genpd) framework somewhat
     (Aisheng Dong).

   - Improve kerneldoc comments for two functions in the cpufreq core
     (Rafael Wysocki).

   - Fix typo in a PM QoS file description comment (Aisheng Dong).

   - Update the handling of CPU boost frequencies in the cpupower
     utility (Abhishek Goel)"

* tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: governor: Add new governors to cpuidle_governors again
  cpufreq: intel_pstate: Fix up iowait_boost computation
  PM / OPP: Update performance state when freq == old_freq
  PM / wakeup: Drop wakeup_source_drop()
  PM / wakeup: Rework wakeup source timer cancellation
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
  OPP: Fix handling of multiple power domains
  PM / QoS: Fix typo in file description
  cpufreq: pxa2xx: remove incorrect __init annotation
  PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
  PM-runtime: Consolidate code to get active/suspended time
  PM: Add and use pr_fmt()
  cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()
  cpuidle: menu: Avoid overflows when computing variance
  tools/power/cpupower: Display boost frequency separately
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more power management updates from Rafael Wysocki:
 "These are mostly fixes and cleanups on top of the previously merged
  power management material for 5.1-rc1 with one cpupower utility update
  that wasn't pushed earlier due to unfortunate timing.

  Specifics:

   - Fix registration of new cpuidle governors partially broken during
     the 5.0 development cycle by mistake (Rafael Wysocki).

   - Avoid integer overflows in the menu cpuidle governor by making it
     discard the overflowing data points upfront (Rafael Wysocki).

   - Fix minor mistake in the recent update of the iowait boost
     computation in the intel_pstate driver (Rafael Wysocki).

   - Drop incorrect __init annotation from one function in the pxa2xx
     cpufreq driver (Arnd Bergmann).

   - Fix the operating performance points (OPP) framework initialization
     for devices in multiple power domains if only one of them is
     scalable (Rajendra Nayak).

   - Fix mistake in dev_pm_opp_set_rate() which causes it to skip
     updating the performance state if the new frequency is the same as
     the old one (Viresh Kumar).

   - Rework the cancellation of wakeup source timers to avoid potential
     issues with it and do some cleanups unlocked by that change (Viresh
     Kumar, Rafael Wysocki).

   - Clean up the code computing the active/suspended time of devices in
     the PM-runtime framework after recent changes (Ulf Hansson).

   - Make the power management infrastructure code use pr_fmt()
     consistently (Joe Perches).

   - Clean up the generic power domains (genpd) framework somewhat
     (Aisheng Dong).

   - Improve kerneldoc comments for two functions in the cpufreq core
     (Rafael Wysocki).

   - Fix typo in a PM QoS file description comment (Aisheng Dong).

   - Update the handling of CPU boost frequencies in the cpupower
     utility (Abhishek Goel)"

* tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: governor: Add new governors to cpuidle_governors again
  cpufreq: intel_pstate: Fix up iowait_boost computation
  PM / OPP: Update performance state when freq == old_freq
  PM / wakeup: Drop wakeup_source_drop()
  PM / wakeup: Rework wakeup source timer cancellation
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
  OPP: Fix handling of multiple power domains
  PM / QoS: Fix typo in file description
  cpufreq: pxa2xx: remove incorrect __init annotation
  PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
  PM-runtime: Consolidate code to get active/suspended time
  PM: Add and use pr_fmt()
  cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()
  cpuidle: menu: Avoid overflows when computing variance
  tools/power/cpupower: Display boost frequency separately
</pre>
</div>
</content>
</entry>
<entry>
<title>PM-runtime: Call pm_runtime_active|suspended_time() from sysfs</title>
<updated>2019-03-07T10:23:17+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-03-05T12:55:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0996584b3026bed7f38abe02e8535e6a6c474118'/>
<id>0996584b3026bed7f38abe02e8535e6a6c474118</id>
<content type='text'>
Avoid the open-coding of the accounted time acquisition in
runtime_active|suspend_time_show() and make them call
pm_runtime_active|suspended_time() instead.

Note that this change also indirectly avoids holding dev-&gt;power.lock
around the do_div() computation and the sprintf() call which is an
additional improvement.

Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
[ rjw: Changelog ]
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>
Avoid the open-coding of the accounted time acquisition in
runtime_active|suspend_time_show() and make them call
pm_runtime_active|suspended_time() instead.

Note that this change also indirectly avoids holding dev-&gt;power.lock
around the do_div() computation and the sprintf() call which is an
additional improvement.

Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM-runtime: Consolidate code to get active/suspended time</title>
<updated>2019-03-07T10:23:17+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-03-05T12:55:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fdc56c073270af2f4d223c96a5fff3048352fc03'/>
<id>fdc56c073270af2f4d223c96a5fff3048352fc03</id>
<content type='text'>
In a step to consolidate the code for fetching the PM-runtime
active/suspended time for a device, add a common function for that
and make the existing pm_runtime_suspended_time() call it.

Also add a corresponding pm_runtime_active_time() calling the new
common function.

Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
[ rjw: Changelog, function rename ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In a step to consolidate the code for fetching the PM-runtime
active/suspended time for a device, add a common function for that
and make the existing pm_runtime_suspended_time() call it.

Also add a corresponding pm_runtime_active_time() calling the new
common function.

Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
[ rjw: Changelog, function rename ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2019-03-06T22:52:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-06T22:52:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e431f2d74e1b91e00e71e97cadcadffc4cda8a9b'/>
<id>e431f2d74e1b91e00e71e97cadcadffc4cda8a9b</id>
<content type='text'>
Pull driver core updates from Greg KH:
 "Here is the big driver core patchset for 5.1-rc1

  More patches than "normal" here this merge window, due to some work in
  the driver core by Alexander Duyck to rework the async probe
  functionality to work better for a number of devices, and independant
  work from Rafael for the device link functionality to make it work
  "correctly".

  Also in here is:

   - lots of BUS_ATTR() removals, the macro is about to go away

   - firmware test fixups

   - ihex fixups and simplification

   - component additions (also includes i915 patches)

   - lots of minor coding style fixups and cleanups.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
  driver core: platform: remove misleading err_alloc label
  platform: set of_node in platform_device_register_full()
  firmware: hardcode the debug message for -ENOENT
  driver core: Add missing description of new struct device_link field
  driver core: Fix PM-runtime for links added during consumer probe
  drivers/component: kerneldoc polish
  async: Add cmdline option to specify drivers to be async probed
  driver core: Fix possible supplier PM-usage counter imbalance
  PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
  driver: platform: Support parsing GpioInt 0 in platform_get_irq()
  selftests: firmware: fix verify_reqs() return value
  Revert "selftests: firmware: remove use of non-standard diff -Z option"
  Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
  device: Fix comment for driver_data in struct device
  kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
  sysfs: remove unused include of kernfs-internal.h
  driver core: Postpone DMA tear-down until after devres release
  driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
  PM-runtime: Take suppliers into account in __pm_runtime_set_status()
  device.h: Add __cold to dev_&lt;level&gt; logging functions
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core updates from Greg KH:
 "Here is the big driver core patchset for 5.1-rc1

  More patches than "normal" here this merge window, due to some work in
  the driver core by Alexander Duyck to rework the async probe
  functionality to work better for a number of devices, and independant
  work from Rafael for the device link functionality to make it work
  "correctly".

  Also in here is:

   - lots of BUS_ATTR() removals, the macro is about to go away

   - firmware test fixups

   - ihex fixups and simplification

   - component additions (also includes i915 patches)

   - lots of minor coding style fixups and cleanups.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
  driver core: platform: remove misleading err_alloc label
  platform: set of_node in platform_device_register_full()
  firmware: hardcode the debug message for -ENOENT
  driver core: Add missing description of new struct device_link field
  driver core: Fix PM-runtime for links added during consumer probe
  drivers/component: kerneldoc polish
  async: Add cmdline option to specify drivers to be async probed
  driver core: Fix possible supplier PM-usage counter imbalance
  PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
  driver: platform: Support parsing GpioInt 0 in platform_get_irq()
  selftests: firmware: fix verify_reqs() return value
  Revert "selftests: firmware: remove use of non-standard diff -Z option"
  Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
  device: Fix comment for driver_data in struct device
  kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
  sysfs: remove unused include of kernfs-internal.h
  driver core: Postpone DMA tear-down until after devres release
  driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
  PM-runtime: Take suppliers into account in __pm_runtime_set_status()
  device.h: Add __cold to dev_&lt;level&gt; logging functions
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge back earlier PM core material for v5.1.</title>
<updated>2019-02-24T20:20:27+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-02-24T20:20:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=656f72bb2ef33cd832a0f8e80893cce09f3d43df'/>
<id>656f72bb2ef33cd832a0f8e80893cce09f3d43df</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>PM-runtime: Fix deadlock when canceling hrtimer</title>
<updated>2019-02-21T09:29:00+00:00</updated>
<author>
<name>Vincent Guittot</name>
<email>vincent.guittot@linaro.org</email>
</author>
<published>2019-02-21T07:59:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=74fb44863084275b952f21ec6a024af0e2e75cb8'/>
<id>74fb44863084275b952f21ec6a024af0e2e75cb8</id>
<content type='text'>
When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.

A deadlock is possible as follows:

CPU0                              CPU1
rpm_resume()
  spin_lock_irqsave
                                  pm_suspend_timer_fn()
                                    spin_lock_irqsave
  pm_runtime_deactivate_timer()
    hrtimer_cancel()

It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev-&gt;power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().

Fixes: 8234f6734c5d ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) &lt;sunzhaosheng@hisilicon.com&gt;
Signed-off-by: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
[ rjw: Changelog ]
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>
When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.

A deadlock is possible as follows:

CPU0                              CPU1
rpm_resume()
  spin_lock_irqsave
                                  pm_suspend_timer_fn()
                                    spin_lock_irqsave
  pm_runtime_deactivate_timer()
    hrtimer_cancel()

It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev-&gt;power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().

Fixes: 8234f6734c5d ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) &lt;sunzhaosheng@hisilicon.com&gt;
Signed-off-by: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Fix PM-runtime for links added during consumer probe</title>
<updated>2019-02-20T10:18:07+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-02-19T16:53:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=36003d4cf57ca431fb3f94d317bcca426a2394d6'/>
<id>36003d4cf57ca431fb3f94d317bcca426a2394d6</id>
<content type='text'>
Commit 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called.  In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".

For this reason, partially revert commit 4c06c4e6cf63 as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former.  [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]

This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.

Fixes: 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Thierry Reding &lt;treding@nvidia.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 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called.  In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".

For this reason, partially revert commit 4c06c4e6cf63 as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former.  [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]

This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.

Fixes: 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Thierry Reding &lt;treding@nvidia.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Fix possible supplier PM-usage counter imbalance</title>
<updated>2019-02-13T08:09:57+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-02-12T12:08:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4c06c4e6cf63d7f3d5dfe62593a073253d750a59'/>
<id>4c06c4e6cf63d7f3d5dfe62593a073253d750a59</id>
<content type='text'>
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.

Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.

To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it.  Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).

Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).

Fixes: e2f3cd831a28 ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&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>
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.

Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.

To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it.  Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).

Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).

Fixes: e2f3cd831a28 ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM-runtime: Fix __pm_runtime_set_status() race with runtime resume</title>
<updated>2019-02-13T08:09:51+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-02-12T12:04:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1567f813a9992a64f8d0f6cfb912c3922812c35'/>
<id>c1567f813a9992a64f8d0f6cfb912c3922812c35</id>
<content type='text'>
Commit 4080ab083000 ("PM-runtime: Take suppliers into account in
__pm_runtime_set_status()") introduced a race condition that may
trigger if __pm_runtime_set_status() is used incorrectly (that is,
if it is called when PM-runtime is enabled for the target device
and working).

In that case, if the original PM-runtime status of the device is
RPM_SUSPENDED, a runtime resume of the device may occur after
__pm_runtime_set_status() has dropped its power.lock spinlock
and before deactivating its suppliers, so the suppliers may be
deactivated while the device is PM-runtime-active which may lead
to functional issues.

To avoid that, modify __pm_runtime_set_status() to check whether
or not PM-runtime is enabled for the device before activating its
suppliers (if the new status is RPM_ACTIVE) and either return an
error if that's the case or increment the device's disable_depth
counter to prevent PM-runtime from being enabled for it while
the remaining part of the function is running (disable_depth is
then decremented on the way out).

Fixes: 4080ab083000 ("PM-runtime: Take suppliers into account in __pm_runtime_set_status()")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&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 4080ab083000 ("PM-runtime: Take suppliers into account in
__pm_runtime_set_status()") introduced a race condition that may
trigger if __pm_runtime_set_status() is used incorrectly (that is,
if it is called when PM-runtime is enabled for the target device
and working).

In that case, if the original PM-runtime status of the device is
RPM_SUSPENDED, a runtime resume of the device may occur after
__pm_runtime_set_status() has dropped its power.lock spinlock
and before deactivating its suppliers, so the suppliers may be
deactivated while the device is PM-runtime-active which may lead
to functional issues.

To avoid that, modify __pm_runtime_set_status() to check whether
or not PM-runtime is enabled for the device before activating its
suppliers (if the new status is RPM_ACTIVE) and either return an
error if that's the case or increment the device's disable_depth
counter to prevent PM-runtime from being enabled for it while
the remaining part of the function is running (disable_depth is
then decremented on the way out).

Fixes: 4080ab083000 ("PM-runtime: Take suppliers into account in __pm_runtime_set_status()")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge 5.0-rc6 into driver-core-next</title>
<updated>2019-02-11T08:09:02+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2019-02-11T08:09:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9481caf39bf55a862067007ffc53621b4305a387'/>
<id>9481caf39bf55a862067007ffc53621b4305a387</id>
<content type='text'>
We need the debugfs fixes in here as well.

Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We need the debugfs fixes in here as well.

Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
