Re: [PATCH v3] usb: core: add sysfs entry for usb device state

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Jun 07, 2023 at 06:58:08PM -0700, Roy Luo wrote:
> > > @@ -160,6 +160,16 @@ static ssize_t connect_type_show(struct device *dev,
> > >  }
> > >  static DEVICE_ATTR_RO(connect_type);
> > >
> > > +static ssize_t state_show(struct device *dev,
> > > +                       struct device_attribute *attr, char *buf)
> > > +{
> > > +     struct usb_port *port_dev = to_usb_port(dev);
> > > +     enum usb_device_state state = READ_ONCE(port_dev->state);
> > > +
> > > +     return sprintf(buf, "%s\n", usb_state_string(state));
> >
> > I thought checkpatch would warn you that you should be using
> > sysfs_emit() here, wonder why it didn't.
> >
> > thanks,
> >
> > greg k-h
> 
> I was using sprintf() instead of sysfs_emit() because I randomly referred
> to one of the nearby attributes. Looks like there are still many attributes in
> port.c that uses sprintf(), any reason why we didn't replace them?
> If not, I'm happy to do a clean-up so that others don't make the same mistake
> as I did :D

Doing whole-scale replacements across the kernel for stuff like this
isn't needed, just for new stuff, using the new apis is a good idea.

thanks,

greg k-h