Re: [PATCH] staging: fieldbus: simplify devm_anybuss_host_common_probe

[tiantao (H)]

在 2021/4/9 19:58, Sven Van Asbroeck 写道:
> Hello Tian, thank you for the contribution. See below.
>
> On Fri, Apr 9, 2021 at 4:33 AM Tian Tao <tiantao6@xxxxxxxxxxxxx> wrote:
> > Use devm_add_action_or_reset() instead of devres_alloc() and
> > devres_add(), which works the same. This will simplify the
> > code. There is no functional changes.
> >
> > Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
> > ---
> >   drivers/staging/fieldbus/anybuss/host.c | 20 ++++++++------------
> >   1 file changed, 8 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
> > index 549cb7d5..2924e68 100644
> > --- a/drivers/staging/fieldbus/anybuss/host.c
> > +++ b/drivers/staging/fieldbus/anybuss/host.c
> > @@ -1406,7 +1406,7 @@ void anybuss_host_common_remove(struct anybuss_host *host)
> >   }
> >   EXPORT_SYMBOL_GPL(anybuss_host_common_remove);
> >
> > -static void host_release(struct device *dev, void *res)
> > +static void host_release(void *res)
> >   {
> >          struct anybuss_host **dr = res;
> You're expecting a double pointer as the argument here...

What about doing it like this?

diff --git a/drivers/staging/fieldbus/anybuss/host.c 
b/drivers/staging/fieldbus/anybuss/host.c
index 549cb7d5..c97df91 100644
--- a/drivers/staging/fieldbus/anybuss/host.c
+++ b/drivers/staging/fieldbus/anybuss/host.c
@@ -1406,32 +1406,26 @@ void anybuss_host_common_remove(struct 
anybuss_host *host)
 }
 EXPORT_SYMBOL_GPL(anybuss_host_common_remove);

-static void host_release(struct device *dev, void *res)
+static void host_release(void *res)
 {
-       struct anybuss_host **dr = res;
-
-       anybuss_host_common_remove(*dr);
+       anybuss_host_common_remove(res);
 }

 struct anybuss_host * __must_check
 devm_anybuss_host_common_probe(struct device *dev,
                               const struct anybuss_ops *ops)
 {
-       struct anybuss_host **dr;
        struct anybuss_host *host;
-
-       dr = devres_alloc(host_release, sizeof(struct anybuss_host *),
-                         GFP_KERNEL);
-       if (!dr)
-               return ERR_PTR(-ENOMEM);
+       int ret;

        host = anybuss_host_common_probe(dev, ops);
-       if (IS_ERR(host)) {
-               devres_free(dr);
+       if (IS_ERR(host))
                return host;
-       }
-       *dr = host;
-       devres_add(dev, dr);
+
+       ret = devm_add_action_or_reset(dev, host_release, host);
+       if (ret)
+               return ERR_PTR(ret);
+
        return host;
 }

> > @@ -1417,21 +1417,17 @@ struct anybuss_host * __must_check
> >   devm_anybuss_host_common_probe(struct device *dev,
> >                                 const struct anybuss_ops *ops)
> >   {
> > -       struct anybuss_host **dr;
> >          struct anybuss_host *host;
> > -
> > -       dr = devres_alloc(host_release, sizeof(struct anybuss_host *),
> > -                         GFP_KERNEL);
> > -       if (!dr)
> > -               return ERR_PTR(-ENOMEM);
> > +       int ret;
> >
> >          host = anybuss_host_common_probe(dev, ops);
> > -       if (IS_ERR(host)) {
> > -               devres_free(dr);
> > +       if (IS_ERR(host))
> >                  return host;
> > -       }
> > -       *dr = host;
> > -       devres_add(dev, dr);
> > +
> > +       ret = devm_add_action_or_reset(dev, host_release, host);
> ... yet you pass in a single pointer here. Is that going to work?
>
> > +       if (ret)
> > +               return ERR_PTR(ret);
> > +
> >          return host;
> >   }
> >   EXPORT_SYMBOL_GPL(devm_anybuss_host_common_probe);
> > --
> > 2.7.4
> .