Re: [PATCH] extcon: usbc-tusb320: Call the Type-C IRQ handler only if a port is registered

[Marek Vasut]

On 11/7/22 16:02, Yassine Oudjana wrote:
> On Mon, Nov 7 2022 at 15:51:55 +01:00:00, Marek Vasut <marex@xxxxxxx> 
> wrote:
> > On 11/7/22 15:48, Yassine Oudjana wrote:
> > > From: Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx>
> > >
> > > Commit bf7571c00dca ("extcon: usbc-tusb320: Add USB TYPE-C support")
> > > added an optional Type-C interface to the driver but missed to check
> > > if it is in use when calling the IRQ handler. This causes an oops on
> > > devices currently using the old extcon interface. Check if a Type-C
> > > port is registered before calling the Type-C IRQ handler.
> > >
> > > Fixes: bf7571c00dca ("extcon: usbc-tusb320: Add USB TYPE-C support")
> > > Signed-off-by: Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx>
> > > ---
> > >   drivers/extcon/extcon-usbc-tusb320.c | 9 ++++++++-
> > >   1 file changed, 8 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/extcon/extcon-usbc-tusb320.c 
> > > b/drivers/extcon/extcon-usbc-tusb320.c
> > > index 41041ff0fadb..037bc11b2a48 100644
> > > --- a/drivers/extcon/extcon-usbc-tusb320.c
> > > +++ b/drivers/extcon/extcon-usbc-tusb320.c
> > > @@ -327,7 +327,14 @@ static irqreturn_t tusb320_irq_handler(int irq, 
> > > void *dev_id)
> > >           return IRQ_NONE;
> > >         tusb320_extcon_irq_handler(priv, reg);
> > > -    tusb320_typec_irq_handler(priv, reg);
> > > +
> > > +    /*
> > > +     * Type-C support is optional for backward compatibility.
> >
> > It's the other way around, extcon is the legacy, type-c is the new, 
> > right ?
>
> Type-C is the new one, yes. This comment is somewhat similar to the one 
> in tusb320_typec_probe():
>
> /* The Type-C connector is optional, for backward compatibility. */

Ahhh, The Type-C connector support is indeed optional to avoid breaking 
any of the older systems which only use/provide extcon.

> Perhaps a better way to say this in both comments would be "to maintain" 
> instead of "for".

I think best just drop the "for backward compatibility" altogether, like so:

/*
 * Type-C support is optional. Only call the Type-C handler if a
 * port had been registered previously.
 */