[PATCH] PM / wakeup: Register wakeup class kobj after device is added

Stephen Boyd
2019-08-16T14:56:05Z

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 986845e747af ("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: 986845e747af ("PM / wakeup: Show wakeup sources stats in sysfs")
Reported-by: Qian Cai <cai@lca.pw>
Cc: Qian Cai <cai@lca.pw>
Cc: Tri Vo <trong@android.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
drivers/base/power/sysfs.c | 10 +++++++++-
drivers/base/power/wakeup.c | 10 ++++++----
2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 1b9c281cbe41..27ee00f50bd7 100644
--- 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"
@@ -661,14 +662,21 @@ int dpm_sysfs_add(struct device *dev)
if (rc)
goto err_runtime;
}
+ if (dev->power.wakeup) {
+ rc = wakeup_source_sysfs_add(dev, dev->power.wakeup);
+ if (rc)
+ goto err_wakeup;
+ }
if (dev->power.set_latency_tolerance) {
rc = sysfs_merge_group(&dev->kobj,
&pm_qos_latency_tolerance_attr_group);
if (rc)
- goto err_wakeup;
+ goto err_wakeup_source;
}
return 0;

+ err_wakeup_source:
+ wakeup_source_sysfs_remove(dev->power.wakeup);
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 f7925820b5ca..5817b51d2b15 100644
--- 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);
}
--
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