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From:   Ricardo Ribalda <ribalda@chromium.org>
Date:   Mon, 28 Nov 2022 10:10:13 +0100
Subject: [PATCH v3 1/2] freezer: Add processes_frozen()
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Message-Id: <20221127-snd-freeze-v3-1-a2eda731ca14@chromium.org>
References: <20221127-snd-freeze-v3-0-a2eda731ca14@chromium.org>
In-Reply-To: <20221127-snd-freeze-v3-0-a2eda731ca14@chromium.org>
To:     Takashi Iwai <tiwai@suse.com>, Len Brown <len.brown@intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Kai Vehmanen <kai.vehmanen@linux.intel.com>,
        Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
        Mark Brown <broonie@kernel.org>,
        Jaroslav Kysela <perex@perex.cz>, Pavel Machek <pavel@ucw.cz>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     alsa-devel@alsa-project.org,
        "Joel Fernandes (Google)" <joel@joelfernandes.org>,
        Ricardo Ribalda <ribalda@chromium.org>,
        linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Precedence: bulk

Add a way to let the drivers know if the processes are frozen.

This is needed by drivers that are waiting for processes to end on their
shutdown path.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 include/linux/freezer.h |  2 ++
 kernel/freezer.c        | 11 +++++++++++
 2 files changed, 13 insertions(+)

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index b303472255be..ca861ace0689 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -47,6 +47,7 @@ extern int freeze_processes(void);
 extern int freeze_kernel_threads(void);
 extern void thaw_processes(void);
 extern void thaw_kernel_threads(void);
+bool processes_frozen(void);
 
 static inline bool try_to_freeze(void)
 {
@@ -80,6 +81,7 @@ static inline int freeze_processes(void) { return -ENOSYS; }
 static inline int freeze_kernel_threads(void) { return -ENOSYS; }
 static inline void thaw_processes(void) {}
 static inline void thaw_kernel_threads(void) {}
+static inline bool processes_frozen(void) { return false; }
 
 static inline bool try_to_freeze(void) { return false; }
 
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 4fad0e6fca64..08828c4e12fd 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -233,3 +233,14 @@ bool set_freezable(void)
 	return try_to_freeze();
 }
 EXPORT_SYMBOL(set_freezable);
+
+/**
+ * processes_frozen - Check if the processes are frozen
+ *
+ * Let drivers know if they shall wait for processes.
+ */
+bool processes_frozen(void)
+{
+	return pm_freezing;
+}
+EXPORT_SYMBOL(processes_frozen);

-- 
2.38.1.584.g0f3c55d4c2-goog-b4-0.11.0-dev-696ae