Messages in this thread | | | From | Ravi Chandra Sadineni <> | Date | Tue, 23 Jul 2019 09:43:55 -0700 | Subject | Re: [PATCH] power:sysfs: Expose device wakeup_event_count. |
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Hi Greg,
On Mon, Jul 22, 2019 at 11:22 AM Greg KH <gregkh@linuxfoundation.org> wrote: > > 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. Corrected the description. > > Is that really a good thing if you are expecting a number? This is to adhere to the convention as described in base/power/sysfs.c. Hope this is o.k > > > + > > 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? power.wakeup can be NULL (device_wakeup_detach ()) if wakeup is disabled for a particular device. > > > + 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 :) Removed the empty lines. > > thanks, > > greg k-h
Thanks, Ravi
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