[ Upstream commit dc351d4c5f4fe4d0f274d6d660227be0c3a03317 ]

The dev->power.direct_complete flag may become set in device_prepare() in
case the device don't have any PM callbacks (dev->power.no_pm_callbacks is
set). This leads to a broken behaviour, when there is child having wakeup
enabled and relies on its parent to be used in the wakeup path.

More precisely, when the direct complete path becomes selected for the
child in __device_suspend(), the propagation of the dev->power.wakeup_path
becomes skipped as well.

Let's address this problem, by checking if the device is a part the wakeup
path or has wakeup enabled, then prevent the direct complete path from
being used.

Reported-by: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Comment cleanup ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Devfreq framework supports suspend of its devices.
Call the the devfreq interface and allow devfreq devices
preserve/restore their states during suspend/resume.

Suggested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

If __device_suspend() runs asynchronously (in which case the device
passed to it is in dpm_suspended_list at that point) and it returns
early on an error or pending wakeup, and the power.direct_complete
flag has been set for the device already, the subsequent
device_resume() will be confused by that and it will call
pm_runtime_enable() incorrectly, as runtime PM has not been
disabled for the device by __device_suspend().

To avoid that, clear power.direct_complete if __device_suspend()
is not going to disable runtime PM for the device before returning.

Fixes: aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily)
Reported-by: Al Cooper <alcooperx@gmail.com>
Tested-by: Al Cooper <alcooperx@gmail.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 08810a4119aa (PM / core: Add NEVER_SKIP and SMART_PREPARE
driver flags) inadvertently prevented the power.direct_complete flag
from being set for devices without PM callbacks and with disabled
runtime PM which also prevents power.direct_complete from being set
for their parents.  That led to problems including a resume crash on
HP ZBook 14u.

Restore the previous behavior by causing power.direct_complete to be
set for those devices again, but do that in a more direct way to
avoid overlooking that case in the future.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199693
Fixes: 08810a4119aa (PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags)
Reported-by: Thomas Martitz <kugel@rockbox.org>
Tested-by: Thomas Martitz <kugel@rockbox.org>
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Johan Hovold <johan@kernel.org>

When we print diagnostic messages about suspend/resume, we have a device
pointer, so use dev_printk() to match other device-related things.  Add the
function name, similar to initcall_debug output.  E.g.,

  - calling  0000:01:00.0+ @ 998, parent: 0000:00:1c.0
  + pci 0000:01:00.0: calling <something> @ 998, parent: 0000:00:1c.0

I wondered if this would break scripts/bootgraph.pl, but I don't think it
will because bootgraph.pl doesn't add any timing information to $start{}
after it sees "Write protecting the" or "Freeing unused kernel memory".

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

initcall_debug_report() always called ktime_get(), even if we didn't
need the result.

Change it so we only call it when we're going to use the result, and
change initcall_debug_start() to follow the same style.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit e8bca479c3f2 (PM / sleep: trace events for device PM callbacks)
removed the only uses of "state" and "info" from initcall_debug_report().

Remove the now-unused arguments completely.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the wakeup_path status flag becomes propagated from a child
device to its parent device at __device_suspend(). This allows a driver
dealing with a parent device to act on the flag from its ->suspend()
callback.

However, in situations when the wakeup_path status flag needs to be set
from a ->suspend_late() callback, its value doesn't get propagated to the
parent by the PM core. Let's address this limitation, by also propagating
the flag at __device_suspend_late().

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

To make the code more consistent, let's clear the parent's direct_complete
flag along with clearing it for suppliers, instead of as currently, when
propagating the wakeup_path flag to parents.

While changing this, let's take the opportunity to rename the affected
internal functions, to make them self-explanatory. Like this:

dpm_clear_suppliers_direct_complete -> dpm_clear_superiors_direct_complete
dpm_propagate_to_parent -> dpm_propagate_wakeup_to_parent

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>