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

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Message-ID: <aOWoX4cqg3fN-pN1@google.com>
Date: Tue, 7 Oct 2025 23:55:11 +0000
From: Benson Leung <bleung@...gle.com>
To: Jameson Thies <jthies@...gle.com>
Cc: heikki.krogerus@...ux.intel.com, 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: Benson Leung <bleung@...omium.org>


> ---
>  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
> 

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