Re: [PATCH v3 1/1] power: Emit changed uevent on wakeup_sysfs_add/remove

[Abhishek Pandit-Subedi <abhishekpandit@chromium.org>]

I admit I didn't test this but I built it with allmodconfig.

Sadly, this only raised a warning instead of an error so I didn't go
look through the build logs (ignore the 5.4, the remote here is the
linux-pm git repo):

/usr/local/google/home/abhishekpandit/chromiumos/src/third_party/kernel/v5.4/drivers/base/power/sysfs.c:
In function ‘wakeup_sysfs_remove’:
/usr/local/google/home/abhishekpandit/chromiumos/src/third_party/kernel/v5.4/drivers/base/power/sysfs.c:754:9:
warning: ‘return’ with a value, in function returning void
[-Wreturn-type]
  754 |  return kobject_uevent(&dev->kobj, KOBJ_CHANGE);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/local/google/home/abhishekpandit/chromiumos/src/third_party/kernel/v5.4/drivers/base/power/sysfs.c:751:6:
note: declared here
  751 | void wakeup_sysfs_remove(struct device *dev)


Will send up another fix.

Thanks
Abhishek

On Tue, Jul 7, 2020 at 9:00 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Jul 07, 2020 at 08:49:05AM -0700, Abhishek Pandit-Subedi wrote:
> > Udev rules that depend on the power/wakeup attribute don't get triggered
> > correctly if device_set_wakeup_capable is called after the device is
> > created. This can happen for several reasons (driver sets wakeup after
> > device is created, wakeup is changed on parent device, etc) and it seems
> > reasonable to emit a changed event when adding or removing attributes on
> > the device.
> >
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > ---
> >
> > Changes in v3:
> > - Simplified error handling
> >
> > Changes in v2:
> > - Add newline at end of bt_dev_err
> >
> >  drivers/base/power/sysfs.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
> > index 24d25cf8ab1487..04c82373c8f240 100644
> > --- a/drivers/base/power/sysfs.c
> > +++ b/drivers/base/power/sysfs.c
> > @@ -1,6 +1,7 @@
> >  // SPDX-License-Identifier: GPL-2.0
> >  /* sysfs entries for device PM */
> >  #include <linux/device.h>
> > +#include <linux/kobject.h>
> >  #include <linux/string.h>
> >  #include <linux/export.h>
> >  #include <linux/pm_qos.h>
> > @@ -739,12 +740,18 @@ int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
> >
> >  int wakeup_sysfs_add(struct device *dev)
> >  {
> > -     return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
> > +     int ret = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
> > +
> > +     if (ret)
> > +             return ret;
> > +
> > +     return kobject_uevent(&dev->kobj, KOBJ_CHANGE);
> >  }
> >
> >  void wakeup_sysfs_remove(struct device *dev)
> >  {
> >       sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
> > +     return kobject_uevent(&dev->kobj, KOBJ_CHANGE);
>
> Always test build and hopefully actually test, your patches before
> sending them out :(
>