Re: [PATCH] powerpc/powernv: use appropiate error code

[Immad Mir]

On 01/09/23 11:10 pm, Christophe Leroy wrote:
> Le 01/09/2023 à 19:19, mirimmad@xxxxxxxxxxx a écrit :
> > [Vous ne recevez pas souvent de courriers de mirimmad@xxxxxxxxxxx. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
> >
> > From: Immad Mir <mirimmad17@xxxxxxxxx>
> >
> > -1 is not a valid error code. This patch replaces it with -EPERM.
> Can you explain how it will work ?
> In scom_debug_init() rc is built by oring the value returned by
> scom_debug_init_one().
> What will be the result when oring some valid values with -EPERM ?
> It was working well with -1 because when you or -1 with anything you get
> -1 as result. But with your change I don't think it will work.


if EPERM is not always necessarily equal to 1, we can put a check in 
scom_debug_init before returning rc. If it is less than 1 (because AFAIK 
or-ring with negative number results back into the same negative number) 
we set rc equal to -1.

Immad.

> Christophe
>
> > Signed-off-by: Immad Mir <mirimmad17@xxxxxxxxx>
> > ---
> >    arch/powerpc/platforms/powernv/opal-xscom.c | 4 ++--
> >    1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c
> > index 262cd6fac..ce4b089dd 100644
> > --- a/arch/powerpc/platforms/powernv/opal-xscom.c
> > +++ b/arch/powerpc/platforms/powernv/opal-xscom.c
> > @@ -171,7 +171,7 @@ static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
> >           if (IS_ERR(dir)) {
> >                   kfree(ent->path.data);
> >                   kfree(ent);
> > -               return -1;
> > +               return -EPERM;
> >           }
> >
> >           debugfs_create_blob("devspec", 0400, dir, &ent->path);
> > @@ -191,7 +191,7 @@ static int scom_debug_init(void)
> >
> >           root = debugfs_create_dir("scom", arch_debugfs_dir);
> >           if (IS_ERR(root))
> > -               return -1;
> > +               return -EPERM;
> >
> >           rc = 0;
> >           for_each_node_with_property(dn, "scom-controller") {
> > --
> > 2.40.0