Re: [PATCH v2] of: __of_update_property_sysfs only call __of_sysfs_remove_bin_file if of_node_is_attached

From: Rob Herring
Date: Mon Sep 10 2018 - 09:47:04 EST


On Mon, Sep 10, 2018 at 4:51 AM Andre Kalb <Andre.Kalb@xxxxxx> wrote:
>
> Hi Frank,
>
> > -----UrsprÃngliche Nachricht-----
> > Von: Frank Rowand [mailto:frowand.list@xxxxxxxxx]
> > Gesendet: Freitag, 7. September 2018 22:01
> > An: Andre Kalb; robh+dt@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx
> > Betreff: Re: [PATCH v2] of: __of_update_property_sysfs only call
> > __of_sysfs_remove_bin_file if of_node_is_attached
> >
> > Hi Andred,
> >
> > On 09/04/18 08:51, Andre Kalb wrote:
> > > To prevent warning "kernfs: can not remove '(null)', no directory" if an overlay
> > isn't applied to the active devicetree.
> > >
> > > Using of_remove_property and then of_add_property doesn't show the
> > warning.

[...]

> > What is the calling path that results in the warning?
> >
> > -Frank
>
> There is the callstack of the warning.
>
> [ 10.782830] ------------[ cut here ]------------
> [ 10.830357] WARNING: CPU: 0 PID: 170 at /linux-4.x/fs/kernfs/dir.c:1276 kernfs_remove_by_name_ns+0x30/0x80()
> [ 10.928997] kernfs: can not remove '(null)', no directory
> [ 10.993107] Modules linked in: module_capemgr(+)
> [ 11.045750] CPU: 0 PID: 170 Comm: systemd-udevd Not tainted 4.4.143-00158-g8e5ca65ec7ee-dirty #114

158 patches on top of an almost 3 year old kernel...

> [ 12.011373] [<bf0000e4>] (module_capemgr_slot_scan [module_capemgr]) from [<bf0007bc>] (module_capemgr_probe+0x3c/0x58 [module_capemgr])

And a driver that's not upstream.

Not saying the fix isn't valid, but please reproduce on recent
mainline. Add a unittest if you have to.

Rob