releases/4.4.181/pm-core-propagate-dev-power.wakeup_path-when-no-call.patch

   1 From 08f456deb611d773872574d5931c710205fad64c Mon Sep 17 00:00:00 2001
   2 From: Ulf Hansson <ulf.hansson@linaro.org>
   3 Date: Wed, 10 Apr 2019 11:55:16 +0200
   4 Subject: PM / core: Propagate dev->power.wakeup_path when no callbacks
   5
   6 [ Upstream commit dc351d4c5f4fe4d0f274d6d660227be0c3a03317 ]
   7
   8 The dev->power.direct_complete flag may become set in device_prepare() in
   9 case the device don't have any PM callbacks (dev->power.no_pm_callbacks is
  10 set). This leads to a broken behaviour, when there is child having wakeup
  11 enabled and relies on its parent to be used in the wakeup path.
  12
  13 More precisely, when the direct complete path becomes selected for the
  14 child in __device_suspend(), the propagation of the dev->power.wakeup_path
  15 becomes skipped as well.
  16
  17 Let's address this problem, by checking if the device is a part the wakeup
  18 path or has wakeup enabled, then prevent the direct complete path from
  19 being used.
  20
  21 Reported-by: Loic Pallardy <loic.pallardy@st.com>
  22 Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
  23 [ rjw: Comment cleanup ]
  24 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  25 Signed-off-by: Sasha Levin <sashal@kernel.org>
  26 ---
  27  drivers/base/power/main.c | 4 ++++
  28  1 file changed, 4 insertions(+)
  29
  30 diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
  31 index 05409141ec077..8efdb823826c8 100644
  32 --- a/drivers/base/power/main.c
  33 +++ b/drivers/base/power/main.c
  34 @@ -1378,6 +1378,10 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
  35         if (dev->power.syscore)
  36                 goto Complete;
  37
  38 +       /* Avoid direct_complete to let wakeup_path propagate. */
  39 +       if (device_may_wakeup(dev) || dev->power.wakeup_path)
  40 +               dev->power.direct_complete = false;
  41 +
  42         if (dev->power.direct_complete) {
  43                 if (pm_runtime_status_suspended(dev)) {
  44                         pm_runtime_disable(dev);
  45 --
  46 2.20.1
  47