From bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Fri, 2 Dec 2022 15:30:28 +0100
Subject: [PATCH] PM: runtime: Do not call __rpm_callback() from rpm_idle()
Git-commit: bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88
Patch-mainline: v6.2-rc1
References: git-fixes

Calling __rpm_callback() from rpm_idle() after adding device links
support to the former is a clear mistake.

Not only it causes rpm_idle() to carry out unnecessary actions, but it
is also against the assumption regarding the stability of PM-runtime
status across __rpm_callback() invocations, because rpm_suspend() and
rpm_resume() may run in parallel with __rpm_callback() when it is called
by rpm_idle() and the device's PM-runtime status can be updated by any
of them.

Fixes: 21d5c57b3726 ("PM / runtime: Use device links")
Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/base/power/runtime.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index b52049098d4e..14088b5adb55 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -484,7 +484,17 @@ static int rpm_idle(struct device *dev, int rpmflags)
 
 	dev->power.idle_notification = true;
 
-	retval = __rpm_callback(callback, dev);
+	if (dev->power.irq_safe)
+		spin_unlock(&dev->power.lock);
+	else
+		spin_unlock_irq(&dev->power.lock);
+
+	retval = callback(dev);
+
+	if (dev->power.irq_safe)
+		spin_lock(&dev->power.lock);
+	else
+		spin_lock_irq(&dev->power.lock);
 
 	dev->power.idle_notification = false;
 	wake_up_all(&dev->power.wait_queue);
-- 
2.35.3