linux-stable.git/drivers/base/power, branch linux-5.17.y

PM: domains: Fix initialization of genpd's next_wakeup

2022-06-09T08:25:56+00:00

[ Upstream commit 622d9b5577f19a6472db21df042fea8f5fefe244 ]

In the genpd governor we walk the list of child-domains to take into
account their next_wakeup. If the child-domain itself, doesn't have a
governor assigned to it, we can end up using the next_wakeup value before
it has been properly initialized. To prevent a possible incorrect behaviour
in the governor, let's initialize next_wakeup to KTIME_MAX.

Fixes: c79aa080fb0f ("PM: domains: use device's next wakeup to determine domain idle state")
Signed-off-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: core: keep irq flags in device_pm_check_callbacks()

2022-04-08T11:58:38+00:00

[ Upstream commit 524bb1da785a7ae43dd413cd392b5071c6c367f8 ]

The function device_pm_check_callbacks() can be called under the spin
lock (in the reported case it happens from genpd_add_device() ->
dev_pm_domain_set(), when the genpd uses spinlocks rather than mutexes.

However this function uncoditionally uses spin_lock_irq() /
spin_unlock_irq(), thus not preserving the CPU flags. Use the
irqsave/irqrestore instead.

The backtrace for the reference:
[    2.752010] ------------[ cut here ]------------
[    2.756769] raw_local_irq_restore() called with IRQs enabled
[    2.762596] WARNING: CPU: 4 PID: 1 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x34/0x50
[    2.772338] Modules linked in:
[    2.775487] CPU: 4 PID: 1 Comm: swapper/0 Tainted: G S                5.17.0-rc6-00384-ge330d0d82eff-dirty #684
[    2.781384] Freeing initrd memory: 46024K
[    2.785839] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    2.785841] pc : warn_bogus_irq_restore+0x34/0x50
[    2.785844] lr : warn_bogus_irq_restore+0x34/0x50
[    2.785846] sp : ffff80000805b7d0
[    2.785847] x29: ffff80000805b7d0 x28: 0000000000000000 x27: 0000000000000002
[    2.785850] x26: ffffd40e80930b18 x25: ffff7ee2329192b8 x24: ffff7edfc9f60800
[    2.785853] x23: ffffd40e80930b18 x22: ffffd40e80930d30 x21: ffff7edfc0dffa00
[    2.785856] x20: ffff7edfc09e3768 x19: 0000000000000000 x18: ffffffffffffffff
[    2.845775] x17: 6572206f74206465 x16: 6c696166203a3030 x15: ffff80008805b4f7
[    2.853108] x14: 0000000000000000 x13: ffffd40e809550b0 x12: 00000000000003d8
[    2.860441] x11: 0000000000000148 x10: ffffd40e809550b0 x9 : ffffd40e809550b0
[    2.867774] x8 : 00000000ffffefff x7 : ffffd40e809ad0b0 x6 : ffffd40e809ad0b0
[    2.875107] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000
[    2.882440] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff7edfc03a8000
[    2.889774] Call trace:
[    2.892290]  warn_bogus_irq_restore+0x34/0x50
[    2.896770]  _raw_spin_unlock_irqrestore+0x94/0xa0
[    2.901690]  genpd_unlock_spin+0x20/0x30
[    2.905724]  genpd_add_device+0x100/0x2d0
[    2.909850]  __genpd_dev_pm_attach+0xa8/0x23c
[    2.914329]  genpd_dev_pm_attach_by_id+0xc4/0x190
[    2.919167]  genpd_dev_pm_attach_by_name+0x3c/0xd0
[    2.924086]  dev_pm_domain_attach_by_name+0x24/0x30
[    2.929102]  psci_dt_attach_cpu+0x24/0x90
[    2.933230]  psci_cpuidle_probe+0x2d4/0x46c
[    2.937534]  platform_probe+0x68/0xe0
[    2.941304]  really_probe.part.0+0x9c/0x2fc
[    2.945605]  __driver_probe_device+0x98/0x144
[    2.950085]  driver_probe_device+0x44/0x15c
[    2.954385]  __device_attach_driver+0xb8/0x120
[    2.958950]  bus_for_each_drv+0x78/0xd0
[    2.962896]  __device_attach+0xd8/0x180
[    2.966843]  device_initial_probe+0x14/0x20
[    2.971144]  bus_probe_device+0x9c/0xa4
[    2.975092]  device_add+0x380/0x88c
[    2.978679]  platform_device_add+0x114/0x234
[    2.983067]  platform_device_register_full+0x100/0x190
[    2.988344]  psci_idle_init+0x6c/0xb0
[    2.992113]  do_one_initcall+0x74/0x3a0
[    2.996060]  kernel_init_freeable+0x2fc/0x384
[    3.000543]  kernel_init+0x28/0x130
[    3.004132]  ret_from_fork+0x10/0x20
[    3.007817] irq event stamp: 319826
[    3.011404] hardirqs last  enabled at (319825): [] __up_console_sem+0x78/0x84
[    3.020332] hardirqs last disabled at (319826): [] el1_dbg+0x24/0x8c
[    3.028458] softirqs last  enabled at (318312): [] _stext+0x410/0x588
[    3.036678] softirqs last disabled at (318299): [] __irq_exit_rcu+0x158/0x174
[    3.045607] ---[ end trace 0000000000000000 ]---

Signed-off-by: Dmitry Baryshkov 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: domains: Fix sleep-in-atomic bug caused by genpd_debug_remove()

2022-04-08T11:57:28+00:00

commit f6bfe8b5b2c2a5ac8bd2fc7bca3706e6c3fc26d8 upstream.

When a genpd with GENPD_FLAG_IRQ_SAFE gets removed, the following
sleep-in-atomic bug will be seen, as genpd_debug_remove() will be called
with a spinlock being held.

[    0.029183] BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1460
[    0.029204] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 1, name: swapper/0
[    0.029219] preempt_count: 1, expected: 0
[    0.029230] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.17.0-rc4+ #489
[    0.029245] Hardware name: Thundercomm TurboX CM2290 (DT)
[    0.029256] Call trace:
[    0.029265]  dump_backtrace.part.0+0xbc/0xd0
[    0.029285]  show_stack+0x3c/0xa0
[    0.029298]  dump_stack_lvl+0x7c/0xa0
[    0.029311]  dump_stack+0x18/0x34
[    0.029323]  __might_resched+0x10c/0x13c
[    0.029338]  __might_sleep+0x4c/0x80
[    0.029351]  down_read+0x24/0xd0
[    0.029363]  lookup_one_len_unlocked+0x9c/0xcc
[    0.029379]  lookup_positive_unlocked+0x10/0x50
[    0.029392]  debugfs_lookup+0x68/0xac
[    0.029406]  genpd_remove.part.0+0x12c/0x1b4
[    0.029419]  of_genpd_remove_last+0xa8/0xd4
[    0.029434]  psci_cpuidle_domain_probe+0x174/0x53c
[    0.029449]  platform_probe+0x68/0xe0
[    0.029462]  really_probe+0x190/0x430
[    0.029473]  __driver_probe_device+0x90/0x18c
[    0.029485]  driver_probe_device+0x40/0xe0
[    0.029497]  __driver_attach+0xf4/0x1d0
[    0.029508]  bus_for_each_dev+0x70/0xd0
[    0.029523]  driver_attach+0x24/0x30
[    0.029534]  bus_add_driver+0x164/0x22c
[    0.029545]  driver_register+0x78/0x130
[    0.029556]  __platform_driver_register+0x28/0x34
[    0.029569]  psci_idle_init_domains+0x1c/0x28
[    0.029583]  do_one_initcall+0x50/0x1b0
[    0.029595]  kernel_init_freeable+0x214/0x280
[    0.029609]  kernel_init+0x2c/0x13c
[    0.029622]  ret_from_fork+0x10/0x20

It doesn't seem necessary to call genpd_debug_remove() with the lock, so
move it out from locking to fix the problem.

Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains")
Signed-off-by: Shawn Guo 
Reviewed-by: Ulf Hansson 
Cc: 5.11+  # 5.11+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: s2idle: ACPI: Fix wakeup interrupts handling

2022-02-07T20:02:31+00:00

After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one discarded by acpi_s2idle_wake() may be missed.  Moreover, if
the SCI triggers again immediately after the rearming in
acpi_s2idle_wake(), that wakeup may be missed too.

The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup()
when pm_wakeup_irq is 0, but that's not the case any more after the
interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is
cleared by the pm_wakeup_clear() call in s2idle_loop().  However,
there may be wakeup interrupts occurring in that time frame and if
that happens, they will be missed.

To address that issue first move the clearing of pm_wakeup_irq to
the point at which it is known that the interrupt causing
acpi_s2idle_wake() to tun will be discarded, before rearming the SCI
for wakeup.  Moreover, because that only reduces the size of the
time window in which the issue may manifest itself, allow
pm_system_irq_wakeup() to register two second wakeup interrupts in
a row and, when discarding the first one, replace it with the second
one.  [Of course, this assumes that only one wakeup interrupt can be
discarded in one go, but currently that is the case and I am not
aware of any plans to change that.]

Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE")
Cc: 5.4+  # 5.4+
Signed-off-by: Rafael J. Wysocki

Merge tag 'rtc-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

2022-01-21T11:13:35+00:00

Pull RTC updates from Alexandre Belloni:
 "Two new drivers this cycle and a significant rework of the CMOS driver
  make the bulk of the changes.

  I also carry powerpc changes with the agreement of Michael.

  New drivers:
   - Sunplus SP7021 RTC
   - Nintendo GameCube, Wii and Wii U RTC

  Driver updates:
   - cmos: refactor UIP handling and presence check, fix century
   - rs5c372: offset correction support, report low voltage
   - rv8803: Epson RX8804 support"

* tag 'rtc-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (33 commits)
  rtc: sunplus: fix return value in sp_rtc_probe()
  rtc: cmos: Evaluate century appropriate
  rtc: gamecube: Fix an IS_ERR() vs NULL check
  rtc: mc146818-lib: fix signedness bug in mc146818_get_time()
  dt-bindings: rtc: qcom-pm8xxx-rtc: update register numbers
  rtc: pxa: fix null pointer dereference
  rtc: ftrtc010: Use platform_get_irq() to get the interrupt
  rtc: Move variable into switch case statement
  rtc: pcf2127: Fix typo in comment
  dt-bindings: rtc: Add Sunplus RTC json-schema
  rtc: Add driver for RTC in Sunplus SP7021
  rtc: rs5c372: fix incorrect oscillation value on r2221tl
  rtc: rs5c372: add offset correction support
  rtc: cmos: avoid UIP when writing alarm time
  rtc: cmos: avoid UIP when reading alarm time
  rtc: mc146818-lib: refactor mc146818_does_rtc_work
  rtc: mc146818-lib: refactor mc146818_get_time
  rtc: mc146818-lib: extract mc146818_avoid_UIP
  rtc: mc146818-lib: fix RTC presence check
  rtc: Check return value from mc146818_get_time()
  ...

PM: runtime: Simplify locking in pm_runtime_put_suppliers()

2021-12-22T17:37:55+00:00

Notice that pm_runtime_put_suppliers() cannot be called with
disabled interrupts, because it may sleep (due to the device
links read locking in the non-SRCU case), and so it can use
spin_lock_irq() and spin_unlock_irq() for the locking.

Update the function accordingly and while at it move the "put"
local variable in it into the inner block where it is used.

This change is not expected to have any visible functional impact.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson

Merge back PM core changes for v5.17.

2021-12-22T17:37:12+00:00

PM: sleep: Fix error handling in dpm_prepare()

2021-12-17T17:36:08+00:00

Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
dpm_list_mtx") forgot to update the while () loop termination
condition to also break the loop if error is nonzero, which
causes the loop to become infinite if device_prepare() returns
an error for one device.

Add the missing !error check.

Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx")
Signed-off-by: Rafael J. Wysocki 
Reported-by: Thomas Hellström 
Reviewed-by: Thomas Hellström 
Reviewed-by: Ulf Hansson 
Cc: All applicable

PM: runtime: Add safety net to supplier device release

2021-12-17T15:25:14+00:00

Because refcount_dec_not_one() returns true if the target refcount
becomes saturated, it is generally unsafe to use its return value as
a loop termination condition, but that is what happens when a device
link's supplier device is released during runtime PM suspend
operations and on device link removal.

To address this, introduce pm_runtime_release_supplier() to be used
in the above cases which will check the supplier device's runtime
PM usage counter in addition to the refcount_dec_not_one() return
value, so the loop can be terminated in case the rpm_active refcount
value becomes invalid, and update the code in question to use it as
appropriate.

This change is not expected to have any visible functional impact.

Reported-by: Peter Zijlstra 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Greg Kroah-Hartman 
Acked-by: Peter Zijlstra (Intel)

PM: runtime: Capture device status before disabling runtime PM

2021-12-17T15:16:40+00:00

In some cases (for example, during system-wide suspend and resume of
devices) it is useful to know whether or not runtime PM has ever been
enabled for a given device and, if so, what the runtime PM status of
it had been right before runtime PM was disabled for it last time.

For this reason, introduce a new struct dev_pm_info field called
last_status that will be used for capturing the runtime PM status of
the device when its power.disable_depth counter changes from 0 to 1.

The new field will be set to RPM_INVALID to start with and whenever
power.disable_depth changes from 1 to 0, so it will be valid only
when runtime PM of the device is currently disabled, but it has been
enabled at least once.

Immediately use power.last_status in rpm_resume() to make it handle
the case when PM runtime is disabled for the device, but its runtime
PM status is RPM_ACTIVE more consistently.  Namely, make it return 1
if power.last_status is also equal to RPM_ACTIVE in that case (the
idea being that if the status was RPM_ACTIVE last time when
power.disable_depth was changing from 0 to 1 and it is still
RPM_ACTIVE, it can be assumed to reflect what happened to the device
last time when it was using runtime PM) and -EACCES otherwise.

Update the documentation to provide a description of last_status and
change the description of pm_runtime_resume() in it to reflect the
new behavior of rpm_active().

While at it, rearrange the code in pm_runtime_enable() to be more
straightforward and replace the WARN() macro in it with a pr_warn()
invocation which is less disruptive.

Link: https://lore.kernel.org/linux-pm/20211026222626.39222-1-ulf.hansson@linaro.org/t/#u
Reviewed-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki