Re: [PATCH 1/3] usb: typec: tcpm: only call get_current_limit() for cc=Rp-def

[André Draszik]

Hi Amit,

On Thu, 2026-10-01 at 22:51 +0000, Amit Sunil Dhamne via B4 Relay wrote:
> From: Amit Sunil Dhamne <amitsd@xxxxxxxxxx>
> 
> tcpm_get_current_limit() folds the default label into the
> TYPEC_CC_RP_DEF case, so tcpc_dev::get_current_limit() is also called
> for CC states that do not advertise Rp, such as TYPEC_CC_OPEN,
> TYPEC_CC_RA and TYPEC_CC_RD. Its kerneldoc has always scoped it to
> cc=Rp-def:
> 
>   @get_current_limit:
>           Optional; called by the tcpm core when configured as a snk
>           and cc=Rp-def. This allows the tcpm to provide a fallback
>           current-limit detection method for the cc=Rp-def case.
> 
> A chip driver has nothing to interpret in the other states. Therefore,
> split the cases and report 0 when CC is not an Rp.
> 
> Assisted-by: LLM
> Signed-off-by: Amit Sunil Dhamne <amitsd@xxxxxxxxxx>
> Reviewed-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> ---
>  drivers/usb/typec/tcpm/tcpm.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 2d6b14aa20856..2e7371ada8642 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -1268,7 +1268,7 @@ static int tcpm_set_vconn(struct tcpm_port *port, bool enable)
>  static u32 tcpm_get_current_limit(struct tcpm_port *port)
>  {
>  	enum typec_cc_status cc;
> -	u32 limit;
> +	u32 limit = 0;

Greedy init is usually not recommended, as it prevents the compiler from
warning about use of a variable without initialising a useful value.

Cheers,
Andre'

>  
>  	cc = port->polarity ? port->cc2 : port->cc1;
>  	switch (cc) {
> @@ -1279,11 +1279,10 @@ static u32 tcpm_get_current_limit(struct tcpm_port *port)
>  		limit = 3000;
>  		break;
>  	case TYPEC_CC_RP_DEF:
> -	default:
>  		if (port->tcpc->get_current_limit)
>  			limit = port->tcpc->get_current_limit(port->tcpc);
> -		else
> -			limit = 0;
> +		break;
> +	default:
>  		break;
>  	}
>