linux-kernel - Re: [PATCH 5/6] usb: typec: ucsi: psy: Set max current to zero when disconnected

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Message-ID: <aOZiNH7UIMlHS2j2@kuha.fi.intel.com>
Date: Wed, 8 Oct 2025 16:08:04 +0300
From: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To: Jameson Thies <jthies@...gle.com>
Cc: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
	dmitry.baryshkov@....qualcomm.com, bleung@...omium.org,
	gregkh@...uxfoundation.org, akuchynski@...omium.org,
	abhishekpandit@...omium.org, sebastian.reichel@...labora.com,
	linux-pm@...r.kernel.org
Subject: Re: [PATCH 5/6] usb: typec: ucsi: psy: Set max current to zero when
 disconnected

On Tue, Oct 07, 2025 at 12:00:06AM +0000, Jameson Thies wrote:
> The ucsi_psy_get_current_max function defaults to 0.1A when it is not
> clear how much current the partner device can support. But this does
> not check the port is connected, and will report 0.1A max current when
> nothing is connected. Update ucsi_psy_get_current_max to report 0A when
> there is no connection.
> 
> Signed-off-by: Jameson Thies <jthies@...gle.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>

> ---
>  drivers/usb/typec/ucsi/psy.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c
> index 985a90d3f898..3a209de55c14 100644
> --- a/drivers/usb/typec/ucsi/psy.c
> +++ b/drivers/usb/typec/ucsi/psy.c
> @@ -169,6 +169,11 @@ static int ucsi_psy_get_current_max(struct ucsi_connector *con,
>  {
>  	u32 pdo;
>  
> +	if (!UCSI_CONSTAT(con, CONNECTED)) {
> +		val->intval = 0;
> +		return 0;
> +	}
> +
>  	switch (UCSI_CONSTAT(con, PWR_OPMODE)) {
>  	case UCSI_CONSTAT_PWR_OPMODE_PD:
>  		if (con->num_pdos > 0) {
> -- 
> 2.51.0.618.g983fd99d29-goog

-- 
heikki