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From: Greg KH <gregkh@linuxfoundation.org>
To: Jameson Thies <jthies@google.com>
Cc: heikki.krogerus@linux.intel.com, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, dmitry.baryshkov@oss.qualcomm.com,
	bleung@chromium.org, akuchynski@chromium.org,
	abhishekpandit@chromium.org, sebastian.reichel@collabora.com,
	kenny@panix.com, linux-pm@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH v2] usb: typec: ucsi: psy: Set max current to zero when disconnected
Date: Sat, 18 Oct 2025 09:28:56 +0200	[thread overview]
Message-ID: <2025101839-startup-backwash-3830@gregkh> (raw)
In-Reply-To: <20251017223053.2415243-1-jthies@google.com>

On Fri, Oct 17, 2025 at 10:30:53PM +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.
> 
> v2 changes:
> - added cc stable tag to commit message
> 
> Fixes: af833e7f7db3 ("usb: typec: ucsi: psy: Set current max to 100mA for BC 1.2 and Default")
> Cc: stable@vger.kernel.org
> Signed-off-by: Jameson Thies <jthies@google.com>
> Reviewed-by: Benson Leung <bleung@chromium.org>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Tested-by: Kenneth R. Crudup <kenny@panix.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 62a9d68bb66d..8ae900c8c132 100644
> --- a/drivers/usb/typec/ucsi/psy.c
> +++ b/drivers/usb/typec/ucsi/psy.c
> @@ -145,6 +145,11 @@ static int ucsi_psy_get_current_max(struct ucsi_connector *con,
>  {
>  	u32 pdo;
>  
> +	if (!UCSI_CONSTAT(con, CONNECTED)) {
> +		val->intval = 0;
> +		return 0;
> +	}

What prevents this from changing right after checking it?

thanks,

greg k-h

  parent reply	other threads:[~2025-10-18  7:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-17 22:30 [PATCH v2] usb: typec: ucsi: psy: Set max current to zero when disconnected Jameson Thies
2025-10-18  7:28 ` Greg KH
2025-10-18  7:28 ` Greg KH [this message]
2025-10-22  0:07   ` Jameson Thies
2025-11-02 23:11 ` Sebastian Reichel

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