From: Zhang Qilong <zhangqilong3@huawei.com>
Date: Tue, 10 Nov 2020 17:29:32 +0800
Subject: PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter
Git-commit: dd8088d5a8969dc2b42f71d7bc01c25c61a78066
Patch-mainline: v5.10-rc5
References: bsc#1183366

In many case, we need to check return value of pm_runtime_get_sync, but
it brings a trouble to the usage counter processing. Many callers forget
to decrease the usage counter when it failed, which could resulted in
reference leak. It has been discussed a lot[0][1]. So we add a function
to deal with the usage counter for better coding.

[0]https://lkml.org/lkml/2020/6/14/88
[1]https://patchwork.ozlabs.org/project/linux-tegra/list/?series=178139
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Acked-by: Rafael J. Wysocki  <rafael.j.wysocki@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 include/linux/pm_runtime.h |   21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -226,6 +226,27 @@ static inline int pm_runtime_get_sync(st
 	return __pm_runtime_resume(dev, RPM_GET_PUT);
 }
 
+/**
+ * pm_runtime_resume_and_get - Bump up usage counter of a device and resume it.
+ * @dev: Target device.
+ *
+ * Resume @dev synchronously and if that is successful, increment its runtime
+ * PM usage counter. Return 0 if the runtime PM usage counter of @dev has been
+ * incremented or a negative error code otherwise.
+ */
+static inline int pm_runtime_resume_and_get(struct device *dev)
+{
+	int ret;
+
+	ret = __pm_runtime_resume(dev, RPM_GET_PUT);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		return ret;
+	}
+
+	return 0;
+}
+
 static inline int pm_runtime_put(struct device *dev)
 {
 	return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC);