PM: sleep: wakeirq: fix wake irq warning in system suspend

When driver uses pm_runtime_force_suspend() as the system suspend callback
function and registers the wake irq with reverse enable ordering, the wake
irq will be re-enabled when entering system suspend, triggering an
'Unbalanced enable for IRQ xxx' warning. In this scenario, the call
sequence during system suspend is as follows:
suspend_devices_and_enter()
-> dpm_suspend_start()
-> dpm_run_callback()
-> pm_runtime_force_suspend()
-> dev_pm_enable_wake_irq_check()
-> dev_pm_enable_wake_irq_complete()

-> suspend_enter()
-> dpm_suspend_noirq()
-> device_wakeup_arm_wake_irqs()
-> dev_pm_arm_wake_irq()

To fix this issue, complete the setting of WAKE_IRQ_DEDICATED_ENABLED flag
in dev_pm_enable_wake_irq_complete() to avoid redundant irq enablement.

Fixes: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming")
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Qingliang Li <qingliang.li@mediatek.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: wakeirq: drop unused enable helpers

Drop the wake-irq enable and disable helpers which have not been used
since commit bed570307ed7 ("PM / wakeirq: Fix dedicated wakeirq for
drivers not using autosuspend").

Note that these functions are essentially just leftovers from the first
iteration of the wake-irq implementation where device drivers were
supposed to call these functions themselves instead of PM core (as
is also indicated by the bogus kernel doc comments).

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: wakeirq: fix wake irq arming

The decision whether to enable a wake irq during suspend can not be done
based on the runtime PM state directly as a driver may use wake irqs
without implementing runtime PM. Such drivers specifically leave the
state set to the default 'suspended' and the wake irq is thus never
enabled at suspend.

Add a new wake irq flag to track whether a dedicated wake irq has been
enabled at runtime suspend and therefore must not be enabled at system
suspend.

Note that pm_runtime_enabled() can not be used as runtime PM is always
disabled during late suspend.

Fixes: 69728051f5bf ("PM / wakeirq: Fix unbalanced IRQ enable for wakeirq")
Cc: 4.16+ <stable@vger.kernel.org> # 4.16+
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: wakeup: Fix typos in comments

Remove the second 'the'.
Replace the second 'of' with 'the'.
Replace 'couter' with 'counter'.

Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: support enabling wake-up irq after runtime_suspend called

When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's ->runtime_suspend() which make it enter low-power state.

e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.

------------------
| ^ ^|
---------------- | | --------------
|<---(0)--->|<--(1)--| (3) (2) (4)

if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
->runtime_suspend().

This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running ->runtime_suspend().

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: wakeirq: drop useless parameter from dev_pm_attach_wake_irq()

This function has the 'irq' parameter which isn't ever used, so drop it.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: wakeirq: Set IRQF_NO_AUTOEN when requesting the IRQ

request_irq() after setting IRQ_NOAUTOEN as below
irq_set_status_flags(irq, IRQ_NOAUTOEN);
request_irq(dev, irq...);
can be replaced by request_irq() with IRQF_NO_AUTOEN flag.

This change is just to simplify the code, no actual functional
changes.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: remove unnecessary parentheses

Remove unnecessary parentheses found by code review.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers: base: power: add proper SPDX identifiers on files that did not have them.

There were a few files in the driver core power code that did not have
SPDX identifiers on them, so fix that up. At the same time, remove the
"free form" text that specified the license of the file, as that is
impossible for any tool to properly parse.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / wakeirq: Add wakeup name to dedicated wake irqs

This makes it easy to grep :wakeup /proc/interrupts.

Suggested-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: Fix unbalanced IRQ enable for wakeirq

If a device is runtime PM suspended when we enter suspend and has
a dedicated wake IRQ, we can get the following warning:

WARNING: CPU: 0 PID: 108 at kernel/irq/manage.c:526 enable_irq+0x40/0x94
[ 102.087860] Unbalanced enable for IRQ 147
...
(enable_irq) from [<c06117a8>] (dev_pm_arm_wake_irq+0x4c/0x60)
(dev_pm_arm_wake_irq) from [<c0618360>]
(device_wakeup_arm_wake_irqs+0x58/0x9c)
(device_wakeup_arm_wake_irqs) from [<c0615948>]
(dpm_suspend_noirq+0x10/0x48)
(dpm_suspend_noirq) from [<c01ac7ac>]
(suspend_devices_and_enter+0x30c/0xf14)
(suspend_devices_and_enter) from [<c01adf20>]
(enter_state+0xad4/0xbd8)
(enter_state) from [<c01ad3ec>] (pm_suspend+0x38/0x98)
(pm_suspend) from [<c01ab3e8>] (state_store+0x68/0xc8)

This is because the dedicated wake IRQ for the device may have been
already enabled earlier by dev_pm_enable_wake_irq_check(). Fix the
issue by checking for runtime PM suspended status.

This issue can be easily reproduced by setting serial console log level
to zero, letting the serial console idle, and suspend the system from
an ssh terminal. On resume, dmesg will have the warning above.

The reason why I have not run into this issue earlier has been that I
typically run my PM test cases from on a serial console instead over ssh.

Fixes: c84345597558 (PM / wakeirq: Enable dedicated wakeirq for suspend)
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeup: Do not fail dev_pm_attach_wake_irq() unnecessarily

Returning an error code from dev_pm_attach_wake_irq() if
device_wakeup_attach_irq() called by it returns an error is
pointless, because the wakeup source used by it may be deleted
by user space via sysfs at any time and in particular right after
dev_pm_attach_wake_irq() has returned. Moreover, it requires
the callers of dev_pm_attach_wake_irq() to create that wakeup
source via device_wakeup_enable() upfront, but that obviously is
racy with respect to the sysfs-based manipulations of it.

To avoid the race, modify device_wakeup_attach_irq() to check
that the wakeup source it is going to use is there (and return
early otherwise), make it void (as it cannot fail after that
change) and make dev_pm_attach_wake_irq() simply call it for
the device unconditionally.

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: report a wakeup_event on dedicated wekup irq

There are two reasons for reporting wakeup event when dedicated wakeup
IRQ is triggered:

- wakeup events accounting, so proper statistical data will be
displayed in sysfs and debugfs;

- there are small window when System is entering suspend during which
dedicated wakeup IRQ can be lost:

dpm_suspend_noirq()
|- device_wakeup_arm_wake_irqs()
|- dev_pm_arm_wake_irq(X)
|- IRQ is enabled and marked as wakeup source
[1]...
|- suspend_device_irqs()
|- suspend_device_irq(X)
|- irqd_set(X, IRQD_WAKEUP_ARMED);
|- wakup IRQ armed

The wakeup IRQ can be lost if it's triggered at point [1]
and not armed yet.

Hence, fix above cases by adding simple pm_wakeup_event() call in
handle_threaded_wake_irq().

Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling)
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
[ tony@atomide.com: added missing return to avoid warnings ]
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: Fix spurious wake-up events for dedicated wakeirqs

Dedicated wakeirq is a one time event to wake-up the system from
low-power state and then call pm_runtime_resume() on the device wired
with the dedicated wakeirq.

Sometimes dedicated wakeirqs can get deferred if they trigger after we
call disable_irq_nosync() in dev_pm_disable_wake_irq(). This can happen
if pm_runtime_get() is called around the same time a wakeirq fires.

If an interrupt fires after disable_irq_nosync(), by default it will get
tagged with IRQS_PENDING and will run later on when the interrupt is
enabled again.

Deferred wakeirqs usually just produce pointless wake-up events. But they
can also cause suspend to fail if the deferred wakeirq fires during
dpm_suspend_noirq() for example. So we really don't want to see the
deferred wakeirqs triggering after the device has resumed.

Let's fix the issue by setting IRQ_DISABLE_UNLAZY flag for the dedicated
wakeirqs. The other option would be to implement irq_disable() in the
dedicated wakeirq controller, but that's not a generic solution.

For reference below is what happens with a IRQ_TYPE_EDGE_BOTH IRQ
type wakeirq:

- resume by dedicated IRQ (EDGE_FALLING)
- suspend_enter()
....
- arch_suspend_enable_irqs()
|- dedicated IRQ armed and fired
|- irq_pm_check_wakeup()
|- disarm, disable IRQ and mark as IRQS_PENDING
....
- dpm_resume_noirq()
|- resume_device_irqs()
|- __enable_irq()
|- check_irq_resend()
|- handle_threaded_wake_irq()
|- dedicated IRQ processed
|- device_wakeup_disarm_wake_irqs()
|- disable_irq_wake()
....
!-> dedicated IRQ (EDGE_RISING)
-| handle_edge_irq()
|- IRQ disabled: mask_ack_irq and mark as IRQS_PENDING
....
- subsequent suspend
....
|- dpm_suspend_noirq()
|- device_wakeup_arm_wake_irqs()
|- __enable_irq()
|- check_irq_resend()
(a) |- handle_threaded_wake_irq()
|- pm_wakeup_event() --> abort suspend
....
|- suspend_device_irqs()
|- suspend_device_irq()
|- dedicated IRQ armed
....
(b) |- resend_irqs
|- irq_pm_check_wakeup()
|- IRQ armed -> abort suspend

because of pending IRQ System suspend can be aborted at points
(a)-not armed or (b)-armed.

Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling)
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
[ tony@atomide.com: added a comment, updated the description ]
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: Enable dedicated wakeirq for suspend

We currently rely on runtime PM to enable dedicated wakeirq for suspend.
This assumption fails in the following two cases:

1. If the consumer driver does not have runtime PM implemented, the
dedicated wakeirq never gets enabled for suspend

2. If the consumer driver has runtime PM implemented, but does not idle
in suspend

Let's fix the issue by always enabling the dedicated wakeirq during
suspend.

Depends-on: bed570307ed7 (PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend)
Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling)
Reported-by: Keerthy <j-keerthy@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
[ tony@atomide.com: updated based on bed570307ed7, added description ]
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend

I noticed some wakeirq flakeyness with consumer drivers not using
autosuspend. For drivers not using autosuspend, the wakeirq may never
get unmasked in rpm_suspend() because of irq desc->depth.

We are configuring dedicated wakeirqs to start with IRQ_NOAUTOEN as we
naturally don't want them running until rpm_suspend() is called.

However, when a consumer driver initially calls pm_runtime_get(), we
now wrongly start with disable_irq_nosync() call on the dedicated
wakeirq that is disabled to start with.

This causes desc->depth to toggle between 1 and 2 instead of the usual
0 and 1. This can prevent enable_irq() from unmasking the wakeirq as
that only happens at desc->depth 1.

This does not necessarily show up with drivers using autosuspend as
there is time for disable_irq_nosync() before rpm_suspend() gets called
after the autosuspend timeout.

Let's fix the issue by adding wirq->status that lazily gets set on
the first rpm_suspend(). We also need PM runtime core private functions
for dev_pm_enable_wake_irq_check() and dev_pm_disable_wake_irq_check()
so we can enable the dedicated wakeirq on the first rpm_suspend().

While at it, let's also fix the comments for dev_pm_enable_wake_irq()
and dev_pm_disable_wake_irq(). Those can still be used by the consumer
drivers as needed because the IRQ core manages the interrupt usecount
for us.

Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling)
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: check that wake IRQ is valid before accepting it

Check that IRQ number passed to dev_pm_set_wake_irq() and
dev_pm_set_dedicated_wake_irq() is valid (not negative) before
accepting it.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeirq: Avoid setting power.wakeirq too hastily

If dev_pm_attach_wake_irq() fails, the device's power.wakeirq field
should not be set to point to the struct wake_irq passed to that
function, as that object will be freed going forward.

For this reason, make dev_pm_attach_wake_irq() first call
device_wakeup_attach_irq() and only set the device's power.wakeirq
field if that's successful.

That requires device_wakeup_attach_irq() to be called under the
device's power.lock lock, but since dev_pm_attach_wake_irq() is
the only caller of it, the requisite changes are easy to make.

Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling)
Reported-by: Felipe Balbi <balbi@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / Wakeirq: Add automated device wake IRQ handling

Turns out we can automate the handling for the device_may_wakeup()
quite a bit by using the kernel wakeup source list as suggested
by Rafael J. Wysocki <rjw@rjwysocki.net>.

And as some hardware has separate dedicated wake-up interrupt
in addition to the IO interrupt, we can automate the handling by
adding a generic threaded interrupt handler that just calls the
device PM runtime to wake up the device.

This allows dropping code from device drivers as we currently
are doing it in multiple ways, and often wrong.

For most drivers, we should be able to drop the following
boilerplate code from runtime_suspend and runtime_resume
functions:

...
device_init_wakeup(dev, true);
...
if (device_may_wakeup(dev))
enable_irq_wake(irq);
...
if (device_may_wakeup(dev))
disable_irq_wake(irq);
...
device_init_wakeup(dev, false);
...

We can replace it with just the following init and exit
time code:

...
device_init_wakeup(dev, true);
dev_pm_set_wake_irq(dev, irq);
...
dev_pm_clear_wake_irq(dev);
device_init_wakeup(dev, false);
...

And for hardware with dedicated wake-up interrupts:

...
device_init_wakeup(dev, true);
dev_pm_set_dedicated_wake_irq(dev, irq);
...
dev_pm_clear_wake_irq(dev);
device_init_wakeup(dev, false);
...

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>