PM / wakeup: Register wakeup class kobj after device is added

The device_set_wakeup_enable() function can be called on a device that
hasn't been registered with device_add() yet. This allows the device to
be in a state where wakeup is enabled for it but the device isn't
published to userspace in sysfs yet.

After commit c8377adfa781 ("PM / wakeup: Show wakeup sources stats in
sysfs"), calling device_set_wakeup_enable() will fail for a device that
hasn't been registered with the driver core via device_add(). This is
because we try to create sysfs entries for the device and associate a
wakeup class kobject with it before the device has been registered.
Let's follow a similar approach that device_set_wakeup_capable() takes
here and register the wakeup class either from
device_set_wakeup_enable() when the device is already registered, or
from dpm_sysfs_add() when the device is being registered with the driver
core via device_add().

Fixes: c8377adfa781 ("PM / wakeup: Show wakeup sources stats in sysfs")
Reported-by: Qian Cai <cai@lca.pw>
Reviewed-by: Tri Vo <trong@android.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index 57b1d1d..39a06a0 100644 (file)
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -157,4 +157,13 @@ extern int wakeup_source_sysfs_add(struct device *parent,
                                   struct wakeup_source *ws);
 extern void wakeup_source_sysfs_remove(struct wakeup_source *ws);
 
+extern int pm_wakeup_source_sysfs_add(struct device *parent);
+
+#else /* !CONFIG_PM_SLEEP */
+
+static inline int pm_wakeup_source_sysfs_add(struct device *parent)
+{
+       return 0;
+}
+
 #endif /* CONFIG_PM_SLEEP */

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 1b9c281..d7d82db 100644 (file)
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -5,6 +5,7 @@
 #include <linux/export.h>
 #include <linux/pm_qos.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_wakeup.h>
 #include <linux/atomic.h>
 #include <linux/jiffies.h>
 #include "power.h"
@@ -667,8 +668,13 @@ int dpm_sysfs_add(struct device *dev)
                if (rc)
                        goto err_wakeup;
        }
+       rc = pm_wakeup_source_sysfs_add(dev);
+       if (rc)
+               goto err_latency;
        return 0;
 
+ err_latency:
+       sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
  err_wakeup:
        sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
  err_runtime:

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 0364695..e58b070 100644 (file)
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -220,10 +220,12 @@ struct wakeup_source *wakeup_source_register(struct device *dev,
 
        ws = wakeup_source_create(name);
        if (ws) {
-               ret = wakeup_source_sysfs_add(dev, ws);
-               if (ret) {
-                       wakeup_source_free(ws);
-                       return NULL;
+               if (!dev || device_is_registered(dev)) {
+                       ret = wakeup_source_sysfs_add(dev, ws);
+                       if (ret) {
+                               wakeup_source_free(ws);
+                               return NULL;
+                       }
                }
                wakeup_source_add(ws);
        }

diff --git a/drivers/base/power/wakeup_stats.c b/drivers/base/power/wakeup_stats.c
index 220a20f..bc5e394 100644 (file)
--- a/drivers/base/power/wakeup_stats.c
+++ b/drivers/base/power/wakeup_stats.c
@@ -184,6 +184,19 @@ int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
 }
 EXPORT_SYMBOL_GPL(wakeup_source_sysfs_add);
 
+/**
+ * pm_wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs
+ * for a device if they're missing.
+ * @parent: Device given wakeup source is associated with
+ */
+int pm_wakeup_source_sysfs_add(struct device *parent)
+{
+       if (!parent->power.wakeup || parent->power.wakeup->dev)
+               return 0;
+
+       return wakeup_source_sysfs_add(parent, parent->power.wakeup);
+}
+
 /**
  * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs.
  * @ws: Wakeup source to be removed from sysfs.