<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/cpuidle, branch linux-5.10.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>sched: idle: Make skipping governor callbacks more consistent</title>
<updated>2026-04-18T08:30:54+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2026-03-07T16:12:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3e84116d45a2f35c6de5aef09e8f305d258fef08'/>
<id>3e84116d45a2f35c6de5aef09e8f305d258fef08</id>
<content type='text'>
[ Upstream commit d557640e4ce589a24dca5ca7ce3b9680f471325f ]

If the cpuidle governor .select() callback is skipped because there
is only one idle state in the cpuidle driver, the .reflect() callback
should be skipped as well, at least for consistency (if not for
correctness), so do it.

Fixes: e5c9ffc6ae1b ("cpuidle: Skip governor when only one idle state is available")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Reviewed-by: Aboorva Devarajan &lt;aboorvad@linux.ibm.com&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Link: https://patch.msgid.link/12857700.O9o76ZdvQC@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 d557640e4ce589a24dca5ca7ce3b9680f471325f ]

If the cpuidle governor .select() callback is skipped because there
is only one idle state in the cpuidle driver, the .reflect() callback
should be skipped as well, at least for consistency (if not for
correctness), so do it.

Fixes: e5c9ffc6ae1b ("cpuidle: Skip governor when only one idle state is available")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Reviewed-by: Aboorva Devarajan &lt;aboorvad@linux.ibm.com&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Link: https://patch.msgid.link/12857700.O9o76ZdvQC@rafael.j.wysocki
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpuidle: Skip governor when only one idle state is available</title>
<updated>2026-03-04T12:19:45+00:00</updated>
<author>
<name>Aboorva Devarajan</name>
<email>aboorvad@linux.ibm.com</email>
</author>
<published>2026-02-16T18:50:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a0f7e804edc82e513d1ccb7c95ed8b351522ec81'/>
<id>a0f7e804edc82e513d1ccb7c95ed8b351522ec81</id>
<content type='text'>
[ Upstream commit e5c9ffc6ae1bcdb1062527d611043681ac301aca ]

On certain platforms (PowerNV systems without a power-mgt DT node),
cpuidle may register only a single idle state. In cases where that
single state is a polling state (state 0), the ladder governor may
incorrectly treat state 1 as the first usable state and pass an
out-of-bounds index. This can lead to a NULL enter callback being
invoked, ultimately resulting in a system crash.

[   13.342636] cpuidle-powernv : Only Snooze is available
[   13.351854] Faulting instruction address: 0x00000000
[   13.376489] NIP [0000000000000000] 0x0
[   13.378351] LR  [c000000001e01974] cpuidle_enter_state+0x2c4/0x668

Fix this by adding a bail-out in cpuidle_select() that returns state 0
directly when state_count &lt;= 1, bypassing the governor and keeping the
tick running.

Fixes: dc2251bf98c6 ("cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol")
Signed-off-by: Aboorva Devarajan &lt;aboorvad@linux.ibm.com&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Link: https://patch.msgid.link/20260216185005.1131593-2-aboorvad@linux.ibm.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 e5c9ffc6ae1bcdb1062527d611043681ac301aca ]

On certain platforms (PowerNV systems without a power-mgt DT node),
cpuidle may register only a single idle state. In cases where that
single state is a polling state (state 0), the ladder governor may
incorrectly treat state 1 as the first usable state and pass an
out-of-bounds index. This can lead to a NULL enter callback being
invoked, ultimately resulting in a system crash.

[   13.342636] cpuidle-powernv : Only Snooze is available
[   13.351854] Faulting instruction address: 0x00000000
[   13.376489] NIP [0000000000000000] 0x0
[   13.378351] LR  [c000000001e01974] cpuidle_enter_state+0x2c4/0x668

Fix this by adding a bail-out in cpuidle_select() that returns state 0
directly when state_count &lt;= 1, bypassing the governor and keeping the
tick running.

Fixes: dc2251bf98c6 ("cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol")
Signed-off-by: Aboorva Devarajan &lt;aboorvad@linux.ibm.com&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Link: https://patch.msgid.link/20260216185005.1131593-2-aboorvad@linux.ibm.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>cpuidle: Fail cpuidle device registration if there is one already</title>
<updated>2025-12-06T21:08:09+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2025-09-19T11:22:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=574112e94a37d310be3949fcfd114c54dff9f990'/>
<id>574112e94a37d310be3949fcfd114c54dff9f990</id>
<content type='text'>
[ Upstream commit 7b1b7961170e4fcad488755e5ffaaaf9bd527e8f ]

Refuse to register a cpuidle device if the given CPU has a cpuidle
device already and print a message regarding it.

Without this, an attempt to register a new cpuidle device without
unregistering the existing one leads to the removal of the existing
cpuidle device without removing its sysfs interface.

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 7b1b7961170e4fcad488755e5ffaaaf9bd527e8f ]

Refuse to register a cpuidle device if the given CPU has a cpuidle
device already and print a message regarding it.

Without this, an attempt to register a new cpuidle device without
unregistering the existing one leads to the removal of the existing
cpuidle device without removing its sysfs interface.

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>Revert "cpuidle: menu: Avoid discarding useful information"</title>
<updated>2025-10-29T13:01:22+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2025-10-18T12:27:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6d18fb4b1e6e77674e51498e05314102f88ce150'/>
<id>6d18fb4b1e6e77674e51498e05314102f88ce150</id>
<content type='text'>
commit 10fad4012234a7dea621ae17c0c9486824f645a0 upstream.

It is reported that commit 85975daeaa4d ("cpuidle: menu: Avoid discarding
useful information") led to a performance regression on Intel Jasper Lake
systems because it reduced the time spent by CPUs in idle state C7 which
is correlated to the maximum frequency the CPUs can get to because of an
average running power limit [1].

Before that commit, get_typical_interval() would have returned UINT_MAX
whenever it had been unable to make a high-confidence prediction which
had led to selecting the deepest available idle state too often and
both power and performance had been inadequate as a result of that on
some systems.  However, this had not been a problem on systems with
relatively aggressive average running power limits, like the Jasper Lake
systems in question, because on those systems it was compensated by the
ability to run CPUs faster.

It was addressed by causing get_typical_interval() to return a number
based on the recent idle duration information available to it even if it
could not make a high-confidence prediction, but that clearly did not
take the possible correlation between idle power and available CPU
capacity into account.

For this reason, revert most of the changes made by commit 85975daeaa4d,
except for one cosmetic cleanup, and add a comment explaining the
rationale for returning UINT_MAX from get_typical_interval() when it
is unable to make a high-confidence prediction.

Fixes: 85975daeaa4d ("cpuidle: menu: Avoid discarding useful information")
Closes: https://lore.kernel.org/linux-pm/36iykr223vmcfsoysexug6s274nq2oimcu55ybn6ww4il3g3cv@cohflgdbpnq7/ [1]
Reported-by: Sergey Senozhatsky &lt;senozhatsky@chromium.org&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/3663603.iIbC2pHGDl@rafael.j.wysocki
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 10fad4012234a7dea621ae17c0c9486824f645a0 upstream.

It is reported that commit 85975daeaa4d ("cpuidle: menu: Avoid discarding
useful information") led to a performance regression on Intel Jasper Lake
systems because it reduced the time spent by CPUs in idle state C7 which
is correlated to the maximum frequency the CPUs can get to because of an
average running power limit [1].

Before that commit, get_typical_interval() would have returned UINT_MAX
whenever it had been unable to make a high-confidence prediction which
had led to selecting the deepest available idle state too often and
both power and performance had been inadequate as a result of that on
some systems.  However, this had not been a problem on systems with
relatively aggressive average running power limits, like the Jasper Lake
systems in question, because on those systems it was compensated by the
ability to run CPUs faster.

It was addressed by causing get_typical_interval() to return a number
based on the recent idle duration information available to it even if it
could not make a high-confidence prediction, but that clearly did not
take the possible correlation between idle power and available CPU
capacity into account.

For this reason, revert most of the changes made by commit 85975daeaa4d,
except for one cosmetic cleanup, and add a comment explaining the
rationale for returning UINT_MAX from get_typical_interval() when it
is unable to make a high-confidence prediction.

Fixes: 85975daeaa4d ("cpuidle: menu: Avoid discarding useful information")
Closes: https://lore.kernel.org/linux-pm/36iykr223vmcfsoysexug6s274nq2oimcu55ybn6ww4il3g3cv@cohflgdbpnq7/ [1]
Reported-by: Sergey Senozhatsky &lt;senozhatsky@chromium.org&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/3663603.iIbC2pHGDl@rafael.j.wysocki
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpuidle: governors: menu: Avoid using invalid recent intervals data</title>
<updated>2025-08-28T14:22:39+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2025-08-11T15:03:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=19a857874baf75f47c8f89504673bf1f7bdb252d'/>
<id>19a857874baf75f47c8f89504673bf1f7bdb252d</id>
<content type='text'>
[ Upstream commit fa3fa55de0d6177fdcaf6fc254f13cc8f33c3eed ]

Marc has reported that commit 85975daeaa4d ("cpuidle: menu: Avoid
discarding useful information") caused the number of wakeup interrupts
to increase on an idle system [1], which was not expected to happen
after merely allowing shallower idle states to be selected by the
governor in some cases.

However, on the system in question, all of the idle states deeper than
WFI are rejected by the driver due to a firmware issue [2].  This causes
the governor to only consider the recent interval duriation data
corresponding to attempts to enter WFI that are successful and the
recent invervals table is filled with values lower than the scheduler
tick period.  Consequently, the governor predicts an idle duration
below the scheduler tick period length and avoids stopping the tick
more often which leads to the observed symptom.

Address it by modifying the governor to update the recent intervals
table also when entering the previously selected idle state fails, so
it knows that the short idle intervals might have been the minority
had the selected idle states been actually entered every time.

Fixes: 85975daeaa4d ("cpuidle: menu: Avoid discarding useful information")
Link: https://lore.kernel.org/linux-pm/86o6sv6n94.wl-maz@kernel.org/ [1]
Link: https://lore.kernel.org/linux-pm/7ffcb716-9a1b-48c2-aaa4-469d0df7c792@arm.com/ [2]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Tested-by: Marc Zyngier &lt;maz@kernel.org&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Link: https://patch.msgid.link/2793874.mvXUDI8C0e@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 fa3fa55de0d6177fdcaf6fc254f13cc8f33c3eed ]

Marc has reported that commit 85975daeaa4d ("cpuidle: menu: Avoid
discarding useful information") caused the number of wakeup interrupts
to increase on an idle system [1], which was not expected to happen
after merely allowing shallower idle states to be selected by the
governor in some cases.

However, on the system in question, all of the idle states deeper than
WFI are rejected by the driver due to a firmware issue [2].  This causes
the governor to only consider the recent interval duriation data
corresponding to attempts to enter WFI that are successful and the
recent invervals table is filled with values lower than the scheduler
tick period.  Consequently, the governor predicts an idle duration
below the scheduler tick period length and avoids stopping the tick
more often which leads to the observed symptom.

Address it by modifying the governor to update the recent intervals
table also when entering the previously selected idle state fails, so
it knows that the short idle intervals might have been the minority
had the selected idle states been actually entered every time.

Fixes: 85975daeaa4d ("cpuidle: menu: Avoid discarding useful information")
Link: https://lore.kernel.org/linux-pm/86o6sv6n94.wl-maz@kernel.org/ [1]
Link: https://lore.kernel.org/linux-pm/7ffcb716-9a1b-48c2-aaa4-469d0df7c792@arm.com/ [2]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Tested-by: Marc Zyngier &lt;maz@kernel.org&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Link: https://patch.msgid.link/2793874.mvXUDI8C0e@rafael.j.wysocki
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpuidle: menu: Avoid discarding useful information</title>
<updated>2025-06-04T12:37:03+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2025-02-06T14:29:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2067fff7222f264e9a8c544cdacff60861568a6a'/>
<id>2067fff7222f264e9a8c544cdacff60861568a6a</id>
<content type='text'>
[ Upstream commit 85975daeaa4d6ec560bfcd354fc9c08ad7f38888 ]

When giving up on making a high-confidence prediction,
get_typical_interval() always returns UINT_MAX which means that the
next idle interval prediction will be based entirely on the time till
the next timer.  However, the information represented by the most
recent intervals may not be completely useless in those cases.

Namely, the largest recent idle interval is an upper bound on the
recently observed idle duration, so it is reasonable to assume that
the next idle duration is unlikely to exceed it.  Moreover, this is
still true after eliminating the suspected outliers if the sample
set still under consideration is at least as large as 50% of the
maximum sample set size.

Accordingly, make get_typical_interval() return the current maximum
recent interval value in that case instead of UINT_MAX.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reported-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Tested-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Tested-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Tested-by: Aboorva Devarajan &lt;aboorvad@linux.ibm.com&gt;
Link: https://patch.msgid.link/7770672.EvYhyI6sBW@rjwysocki.net
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 85975daeaa4d6ec560bfcd354fc9c08ad7f38888 ]

When giving up on making a high-confidence prediction,
get_typical_interval() always returns UINT_MAX which means that the
next idle interval prediction will be based entirely on the time till
the next timer.  However, the information represented by the most
recent intervals may not be completely useless in those cases.

Namely, the largest recent idle interval is an upper bound on the
recently observed idle duration, so it is reasonable to assume that
the next idle duration is unlikely to exceed it.  Moreover, this is
still true after eliminating the suspected outliers if the sample
set still under consideration is at least as large as 50% of the
maximum sample set size.

Accordingly, make get_typical_interval() return the current maximum
recent interval value in that case instead of UINT_MAX.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reported-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Tested-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Reviewed-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Tested-by: Christian Loehle &lt;christian.loehle@arm.com&gt;
Tested-by: Aboorva Devarajan &lt;aboorvad@linux.ibm.com&gt;
Link: https://patch.msgid.link/7770672.EvYhyI6sBW@rjwysocki.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT</title>
<updated>2023-09-19T10:20:15+00:00</updated>
<author>
<name>Russell Currey</name>
<email>ruscur@russell.cc</email>
</author>
<published>2023-08-23T05:53:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=953c54dfdc5d3eb7243ed902b50acb5ea1db4355'/>
<id>953c54dfdc5d3eb7243ed902b50acb5ea1db4355</id>
<content type='text'>
[ Upstream commit eac030b22ea12cdfcbb2e941c21c03964403c63f ]

lppaca_shared_proc() takes a pointer to the lppaca which is typically
accessed through get_lppaca().  With DEBUG_PREEMPT enabled, this leads
to checking if preemption is enabled, for example:

  BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693
  caller is lparcfg_data+0x408/0x19a0
  CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2
  Call Trace:
    dump_stack_lvl+0x154/0x200 (unreliable)
    check_preemption_disabled+0x214/0x220
    lparcfg_data+0x408/0x19a0
    ...

This isn't actually a problem however, as it does not matter which
lppaca is accessed, the shared proc state will be the same.
vcpudispatch_stats_procfs_init() already works around this by disabling
preemption, but the lparcfg code does not, erroring any time
/proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled.

Instead of disabling preemption on the caller side, rework
lppaca_shared_proc() to not take a pointer and instead directly access
the lppaca, bypassing any potential preemption checks.

Fixes: f13c13a00512 ("powerpc: Stop using non-architected shared_proc field in lppaca")
Signed-off-by: Russell Currey &lt;ruscur@russell.cc&gt;
[mpe: Rework to avoid needing a definition in paca.h and lppaca.h]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230823055317.751786-4-mpe@ellerman.id.au
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 eac030b22ea12cdfcbb2e941c21c03964403c63f ]

lppaca_shared_proc() takes a pointer to the lppaca which is typically
accessed through get_lppaca().  With DEBUG_PREEMPT enabled, this leads
to checking if preemption is enabled, for example:

  BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693
  caller is lparcfg_data+0x408/0x19a0
  CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2
  Call Trace:
    dump_stack_lvl+0x154/0x200 (unreliable)
    check_preemption_disabled+0x214/0x220
    lparcfg_data+0x408/0x19a0
    ...

This isn't actually a problem however, as it does not matter which
lppaca is accessed, the shared proc state will be the same.
vcpudispatch_stats_procfs_init() already works around this by disabling
preemption, but the lparcfg code does not, erroring any time
/proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled.

Instead of disabling preemption on the caller side, rework
lppaca_shared_proc() to not take a pointer and instead directly access
the lppaca, bypassing any potential preemption checks.

Fixes: f13c13a00512 ("powerpc: Stop using non-architected shared_proc field in lppaca")
Signed-off-by: Russell Currey &lt;ruscur@russell.cc&gt;
[mpe: Rework to avoid needing a definition in paca.h and lppaca.h]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230823055317.751786-4-mpe@ellerman.id.au
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpuidle: psci: Iterate backwards over list in psci_pd_remove()</title>
<updated>2023-03-22T12:30:05+00:00</updated>
<author>
<name>Shawn Guo</name>
<email>shawn.guo@linaro.org</email>
</author>
<published>2023-03-04T07:41:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=15e926dfd82081e759754ac3917817d427ec2889'/>
<id>15e926dfd82081e759754ac3917817d427ec2889</id>
<content type='text'>
commit 6b0313c2fa3d2cf991c9ffef6fae6e7ef592ce6d upstream.

In case that psci_pd_init_topology() fails for some reason,
psci_pd_remove() will be responsible for deleting provider and removing
genpd from psci_pd_providers list.  There will be a failure when removing
the cluster PD, because the cpu (child) PDs haven't been removed.

[    0.050232] CPUidle PSCI: init PM domain cpu0
[    0.050278] CPUidle PSCI: init PM domain cpu1
[    0.050329] CPUidle PSCI: init PM domain cpu2
[    0.050370] CPUidle PSCI: init PM domain cpu3
[    0.050422] CPUidle PSCI: init PM domain cpu-cluster0
[    0.050475] PM: genpd_remove: unable to remove cpu-cluster0
[    0.051412] PM: genpd_remove: removed cpu3
[    0.051449] PM: genpd_remove: removed cpu2
[    0.051499] PM: genpd_remove: removed cpu1
[    0.051546] PM: genpd_remove: removed cpu0

Fix the problem by iterating the provider list reversely, so that parent
PD gets removed after child's PDs like below.

[    0.029052] CPUidle PSCI: init PM domain cpu0
[    0.029076] CPUidle PSCI: init PM domain cpu1
[    0.029103] CPUidle PSCI: init PM domain cpu2
[    0.029124] CPUidle PSCI: init PM domain cpu3
[    0.029151] CPUidle PSCI: init PM domain cpu-cluster0
[    0.029647] PM: genpd_remove: removed cpu0
[    0.029666] PM: genpd_remove: removed cpu1
[    0.029690] PM: genpd_remove: removed cpu2
[    0.029714] PM: genpd_remove: removed cpu3
[    0.029738] PM: genpd_remove: removed cpu-cluster0

Fixes: a65a397f2451 ("cpuidle: psci: Add support for PM domains by using genpd")
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Shawn Guo &lt;shawn.guo@linaro.org&gt;
Cc: 5.10+ &lt;stable@vger.kernel.org&gt; # 5.10+
Signed-off-by: Rafael J. Wysocki &lt;rjw@rjwysocki.net&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 6b0313c2fa3d2cf991c9ffef6fae6e7ef592ce6d upstream.

In case that psci_pd_init_topology() fails for some reason,
psci_pd_remove() will be responsible for deleting provider and removing
genpd from psci_pd_providers list.  There will be a failure when removing
the cluster PD, because the cpu (child) PDs haven't been removed.

[    0.050232] CPUidle PSCI: init PM domain cpu0
[    0.050278] CPUidle PSCI: init PM domain cpu1
[    0.050329] CPUidle PSCI: init PM domain cpu2
[    0.050370] CPUidle PSCI: init PM domain cpu3
[    0.050422] CPUidle PSCI: init PM domain cpu-cluster0
[    0.050475] PM: genpd_remove: unable to remove cpu-cluster0
[    0.051412] PM: genpd_remove: removed cpu3
[    0.051449] PM: genpd_remove: removed cpu2
[    0.051499] PM: genpd_remove: removed cpu1
[    0.051546] PM: genpd_remove: removed cpu0

Fix the problem by iterating the provider list reversely, so that parent
PD gets removed after child's PDs like below.

[    0.029052] CPUidle PSCI: init PM domain cpu0
[    0.029076] CPUidle PSCI: init PM domain cpu1
[    0.029103] CPUidle PSCI: init PM domain cpu2
[    0.029124] CPUidle PSCI: init PM domain cpu3
[    0.029151] CPUidle PSCI: init PM domain cpu-cluster0
[    0.029647] PM: genpd_remove: removed cpu0
[    0.029666] PM: genpd_remove: removed cpu1
[    0.029690] PM: genpd_remove: removed cpu2
[    0.029714] PM: genpd_remove: removed cpu3
[    0.029738] PM: genpd_remove: removed cpu-cluster0

Fixes: a65a397f2451 ("cpuidle: psci: Add support for PM domains by using genpd")
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Shawn Guo &lt;shawn.guo@linaro.org&gt;
Cc: 5.10+ &lt;stable@vger.kernel.org&gt; # 5.10+
Signed-off-by: Rafael J. Wysocki &lt;rjw@rjwysocki.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpuidle: dt: Return the correct numbers of parsed idle states</title>
<updated>2023-01-14T09:15:15+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2022-10-21T15:10:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1498d2723e74eac6fb06100eeaeca560c57d754e'/>
<id>1498d2723e74eac6fb06100eeaeca560c57d754e</id>
<content type='text'>
[ Upstream commit ee3c2c8ad6ba6785f14a60e4081d7c82e88162a2 ]

While we correctly skips to initialize an idle state from a disabled idle
state node in DT, the returned value from dt_init_idle_driver() don't get
adjusted accordingly. Instead the number of found idle state nodes are
returned, while the callers are expecting the number of successfully
initialized idle states from DT.

This leads to cpuidle drivers unnecessarily continues to initialize their
idle state specific data. Moreover, in the case when all idle states have
been disabled in DT, we would end up registering a cpuidle driver, rather
than relying on the default arch specific idle call.

Fixes: 9f14da345599 ("drivers: cpuidle: implement DT based idle states infrastructure")
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.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 ee3c2c8ad6ba6785f14a60e4081d7c82e88162a2 ]

While we correctly skips to initialize an idle state from a disabled idle
state node in DT, the returned value from dt_init_idle_driver() don't get
adjusted accordingly. Instead the number of found idle state nodes are
returned, while the callers are expecting the number of successfully
initialized idle states from DT.

This leads to cpuidle drivers unnecessarily continues to initialize their
idle state specific data. Moreover, in the case when all idle states have
been disabled in DT, we would end up registering a cpuidle driver, rather
than relying on the default arch specific idle call.

Fixes: 9f14da345599 ("drivers: cpuidle: implement DT based idle states infrastructure")
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.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>cpuidle: Fix kobject memory leaks in error paths</title>
<updated>2021-11-18T13:04:05+00:00</updated>
<author>
<name>Anel Orazgaliyeva</name>
<email>anelkz@amazon.de</email>
</author>
<published>2021-09-06T18:34:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f03e0624e927579376fb0a7f260d5de4dfd4ecfc'/>
<id>f03e0624e927579376fb0a7f260d5de4dfd4ecfc</id>
<content type='text'>
[ Upstream commit e5f5a66c9aa9c331da5527c2e3fd9394e7091e01 ]

Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
fixes the cleanup of kobjects; however, it removes kfree() calls
altogether, leading to memory leaks.

Fix those and also defer the initialization of dev-&gt;kobj_dev until
after the error check, so that we do not end up with a dangling
pointer.

Fixes: c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
Signed-off-by: Anel Orazgaliyeva &lt;anelkz@amazon.de&gt;
Suggested-by: Aman Priyadarshi &lt;apeureka@amazon.de&gt;
[ rjw: Subject edits ]
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 e5f5a66c9aa9c331da5527c2e3fd9394e7091e01 ]

Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
fixes the cleanup of kobjects; however, it removes kfree() calls
altogether, leading to memory leaks.

Fix those and also defer the initialization of dev-&gt;kobj_dev until
after the error check, so that we do not end up with a dangling
pointer.

Fixes: c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
Signed-off-by: Anel Orazgaliyeva &lt;anelkz@amazon.de&gt;
Suggested-by: Aman Priyadarshi &lt;apeureka@amazon.de&gt;
[ rjw: Subject edits ]
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>
