linux-kernel - Re: [PATCH v1 1/3] usb: typec: intel_pmc_mux: Put fwnode in error case during ->probe()

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Message-ID: <YL3rkZd/2giR+Qok@kuha.fi.intel.com>
Date:   Mon, 7 Jun 2021 12:49:05 +0300
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        USB <linux-usb@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1 1/3] usb: typec: intel_pmc_mux: Put fwnode in error
 case during ->probe()

On Mon, Jun 07, 2021 at 12:29:53PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 7, 2021 at 12:23 PM Heikki Krogerus
> <heikki.krogerus@...ux.intel.com> wrote:
> > On Sun, Jun 06, 2021 at 11:09:09PM +0300, Andy Shevchenko wrote:
> > > device_get_next_child_node() bumps a reference counting of a returned variable.
> 
> ...
> 
> > >  err_remove_ports:
> > > +     fwnode_handle_put(fwnode);
> >
> > Wouldn't it be more clear to do that in the condition that jumps to
> > this lable?
> 
> In this case it doesn't matter. As a general pattern, no, because this
> will help to keep this in mind in complex error handling ladders. That
> said, I prefer my variant unless there is a strong opinion to move it
> into the conditional.

Now it looks like you are releasing the mux device fwnode instead of a
port fwnode because everything else related to the ports is destroyed
in below loop. That's too confusing.

Just handle it inside the condition, and the whole thing becomes
clear.

> > >       for (i = 0; i < pmc->num_ports; i++) {
> > >               typec_switch_unregister(pmc->port[i].typec_sw);
> > >               typec_mux_unregister(pmc->port[i].typec_mux);

-- 
heikki