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

[Marek Vasut <marex@denx.de>]

On 11/7/22 16:02, Yassine Oudjana wrote:
> 
> On Mon, Nov 7 2022 at 15:51:55 +01:00:00, Marek Vasut <marex@denx.de> 
> wrote:
>> On 11/7/22 15:48, Yassine Oudjana wrote:
>>> From: Yassine Oudjana <y.oudjana@protonmail.com>
>>>
>>> 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@protonmail.com>
>>> ---
>>>   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;
>>>   \x7f      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.
  */