Messages in this thread | | | Date | Mon, 22 Jul 2019 20:22:52 +0200 | From | Greg KH <> | Subject | Re: [PATCH] power:sysfs: Expose device wakeup_event_count. |
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On Mon, Jul 22, 2019 at 11:02:58AM -0700, Ravi Chandra Sadineni wrote: > Device level event_count can help user level daemon to track if a > praticular device has seen an wake interrupt during a suspend resume > cycle. Thus expose it via sysfs. > > Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org> > --- > Documentation/ABI/testing/sysfs-devices-power | 11 ++++++++++ > drivers/base/power/sysfs.c | 20 +++++++++++++++++++ > 2 files changed, 31 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power > index 1ca04b4f0489..344549f4013f 100644 > --- a/Documentation/ABI/testing/sysfs-devices-power > +++ b/Documentation/ABI/testing/sysfs-devices-power > @@ -89,6 +89,17 @@ Description: > attribute is not present. If the device is not enabled to wake > up the system from sleep states, this attribute is empty. > > +What: /sys/devices/.../power/wakeup_event_count > +Date: July 2019 > +Contact: Ravi Chandra sadineni <ravisadineni@chromium.org> > +Description: > + The /sys/devices/.../wakeup_event_count attribute contains the > + number of signaled wakeup events associated with the device. > + This attribute is read-only. If the device is not capable to > + wake up the system from sleep states, this attribute is not > + present. If the device is not enabled to wake up the system > + from sleep states, this attribute is empty.
The attribute is not "empty" it returns just an empty line.
Is that really a good thing if you are expecting a number?
> + > What: /sys/devices/.../power/wakeup_active_count > Date: September 2010 > Contact: Rafael J. Wysocki <rjw@rjwysocki.net> > diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c > index f42044d9711c..8dc1235b9784 100644 > --- a/drivers/base/power/sysfs.c > +++ b/drivers/base/power/sysfs.c > @@ -357,6 +357,25 @@ static ssize_t wakeup_count_show(struct device *dev, > > static DEVICE_ATTR_RO(wakeup_count); > > +static ssize_t wakeup_event_count_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + unsigned long count = 0; > + bool enabled = false; > + > + spin_lock_irq(&dev->power.lock); > + if (dev->power.wakeup) { > + count = dev->power.wakeup->event_count; > + enabled = true; > + } > + spin_unlock_irq(&dev->power.lock);
Why do you need to lock? The state and count can change right after the lock, so what does this help with?
> + return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
Use a real if statement please.
> +} > + > +static DEVICE_ATTR_RO(wakeup_event_count); > + > + > +
too many empty lines :)
thanks,
greg k-h
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