Hi Andy,
On Mon, 5 Aug 2024 22:20:56 +0200
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:
> On Mon, Aug 5, 2024 at 12:19 PM Herve Codina <herve.codina@xxxxxxxxxxx> wrote:
> >
> > From: Clément Léger <clement.leger@xxxxxxxxxxx>
> >
> > Syscon releasing is not supported.
> > Without release function, unbinding a driver that uses syscon whether
> > explicitly or due to a module removal left the used syscon in a in-use
> > state.
> >
> > For instance a syscon_node_to_regmap() call from a consumer retrieve a
>
> retrieves?
Indeed, will be fixed.
>
> > syscon regmap instance. Internally, syscon_node_to_regmap() can create
> > syscon instance and add it to the existing syscon list. No API is
> > available to release this syscon instance, remove it from the list and
> > free it when it is not used anymore.
> >
> > Introduce reference counting in syscon in order to keep track of syscon
> > usage using syscon_{get,put}() and add a device managed version of
> > syscon_regmap_lookup_by_phandle(), to automatically release the syscon
> > instance on the consumer removal.
>
> ...
>
> > - if (!syscon)
> > + if (!syscon) {
> > syscon = of_syscon_register(np, check_res);
> > + if (IS_ERR(syscon))
> > + return ERR_CAST(syscon);
> > + } else {
> > + syscon_get(syscon);
> > + }
>
> if (syscon)
> return syscon_get();
>
> ?
>
> > + return syscon;
Yes and further more, I will remove also the unneeded IS_ERR() and ERR_CAST().
This will lead to just:
if (syscon)
return syscon_get(syscon);
return of_syscon_register(np, check_res);
>
> ...
>
> > +static struct regmap *__devm_syscon_get(struct device *dev,
> > + struct syscon *syscon)
> > +{
> > + struct syscon **ptr;
> > +
> > + if (IS_ERR(syscon))
> > + return ERR_CAST(syscon);
> > +
> > + ptr = devres_alloc(devm_syscon_release, sizeof(struct syscon *), GFP_KERNEL);
> > + if (!ptr) {
> > + syscon_put(syscon);
> > + return ERR_PTR(-ENOMEM);
> > + }
> > +
> > + *ptr = syscon;
> > + devres_add(dev, ptr);
> > +
> > + return syscon->regmap;
>
> Can't the devm_add_action_or_reset() be used in this case? If so,
> perhaps a comment to explain why?
There is no reason to avoid the use of devm_add_action_or_reset() here.
So, I will use it in the next iteration.
Thanks for your review.
Best regards,
Hervé
