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Date: Sun, 24 Mar 2024 16:08:28 +0100
From: Marek =?UTF-8?B?QmVow7pu?= <kabel@kernel.org>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
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Subject: Re: [PATCH v5 08/11] devm-helpers: Add resource managed version of
 debugfs directory create function
Message-ID: <20240324160828.7f873a96@thinkpad>
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On Sun, 24 Mar 2024 10:21:28 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> Le 23/03/2024 =C3=A0 22:25, Marek Beh=C3=BAn a =C3=A9crit=C2=A0:
> > On Sat, 23 Mar 2024 22:10:40 +0100
> > Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:
> >  =20
>=20
> ...
>=20
> >>>    static int pvt_ts_dbgfs_create(struct pvt_device *pvt, struct devi=
ce *dev)
> >>>    {
> >>> -	pvt->dbgfs_dir =3D debugfs_create_dir(dev_name(dev), NULL);
> >>> +	pvt->dbgfs_dir =3D devm_debugfs_create_dir(dev, dev_name(dev), NULL=
);
> >>> +	if (IS_ERR(pvt->dbgfs_dir))
> >>> +		return PTR_ERR(pvt->dbgfs_dir); =20
> >>
> >> Not sure if the test and error handling should be added here.
> >> *If I'm correct*, functions related to debugfs already handle this case
> >> and just do nothing. And failure in debugfs related code is not
> >> considered as something that need to be reported and abort a probe fun=
ction.
> >>
> >> Maybe the same other (already existing) tests in this patch should be
> >> removed as well, in a separated patch. =20
> >=20
> > Functions related to debugfs maybe do, but devm_ resource management
> > functions may fail to allocate release structure, and those errors need
> > to be handled, AFAIK. =20
>=20
> I would say no.
> If this memory allocation fails, then debugfs_create_dir() will not be=20
> called, but that's not a really big deal if the driver itself can still=20
> run normally without it.

debugfs_create_dir() will always be called. Resource allocation is done
afterwards, and if it fails, then the created dir will be removed.

But now I don't know what to do, because yes, it seems that the debugfs
errors are being ignored at many places...

>=20
> Up to you to leave it as-is or remove what I think is a useless error=20
> handling.
> At least, maybe it could be said in the commit log, so that maintainers=20
> can comment on it, if they don't spot the error handling you introduce.
>=20
> CJ
>=20
> >=20
> > Marek
> >  =20
>=20