[PATCH v2] component: do not leave master devres group open after bind

[Kai Vehmanen]

Hey,

On Tue, 28 Sep 2021, Takashi Iwai wrote:

> On Wed, 22 Sep 2021 10:54:32 +0200, Kai Vehmanen wrote:
> > --- a/drivers/base/component.c
> > +++ b/drivers/base/component.c
> > @@ -246,7 +246,7 @@ static int try_to_bring_up_master(struct master *master,
> >  		return 0;
> >  	}
> >  
> > -	if (!devres_open_group(master->parent, NULL, GFP_KERNEL))
> > +	if (!devres_open_group(master->parent, master, GFP_KERNEL))
> >  		return -ENOMEM;
> >  
> >  	/* Found all components */
> > @@ -258,6 +258,7 @@ static int try_to_bring_up_master(struct master *master,
> >  		return ret;
> >  	}
> >  
> > +	devres_close_group(master->parent, NULL);
> 
> Just wondering whether we should pass master here instead of NULL,
> too?

I wondered about this as well. Functionally it should be equivalent as 
passing NULL will apply the operation to the latest added group. I noted 
the practise of passing NULL has been followed in the existing code when 
referring to groups created within the same function. E.g.

»       if (!devres_open_group(component->dev, component, GFP_KERNEL)) {
[...]
»       ret = component->ops->bind(component->dev, master->parent, data);
»       if (!ret) {
»       »       component->bound = true;

»       »       /*                                                                                                                                                          
»       »        * Close the component device's group so that resources                                                                                                     
»       »        * allocated in the binding are encapsulated for removal                                                                                                    
»       »        * at unbind.  Remove the group on the DRM device as we                                                                                                     
»       »        * can clean those resources up independently.                                                                                                              
»       »        */
»       »       devres_close_group(component->dev, NULL);

... so I followed this existing practise. I can change and send a V3 if 
the explicit parameter is preferred.

Br, Kai