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Date: Mon, 10 Jun 2024 16:08:35 +0300
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Mark Pearson <mpearson-lenovo@squebb.ca>
Cc: diogo.ivo@siemens.com, dmitry.baryshkov@linaro.org,
	gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: typec: ucsi: don't retrieve PDOs if not supported
Message-ID: <Zmb605vjKBNS+lDn@kuha.fi.intel.com>
References: <mpearson-lenovo@squebb.ca>
 <20240609214328.6580-1-mpearson-lenovo@squebb.ca>
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In-Reply-To: <20240609214328.6580-1-mpearson-lenovo@squebb.ca>

On Sun, Jun 09, 2024 at 05:43:18PM -0400, Mark Pearson wrote:
> On systems where the UCSI PDOs are not supported, the UCSI driver is
> giving an error message. This can cause users to believe there is a HW
> issue with their system when in fact it is working as designed.
> 
> Check if PDO_DETAILS are supported as a feature before attempting to
> access PDO. If not supported return that zero PDOs are available.
> 
> Tested on Lenovo L14 G5 AMD and confirmed with Lenovo FW team that PDOs
> are not supported on this platform.
> 
> Suggested-by: Diogo Ivo <diogo.ivo@siemens.com>
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>

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

> ---
> Note this patch replaces my previous submission 'treat get_pdos not supported
> condition as info instead of error', based on feedback from review.
> 
>  drivers/usb/typec/ucsi/ucsi.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index cb52e7b0a2c5..cadea8d328ed 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -641,9 +641,13 @@ static int ucsi_read_pdos(struct ucsi_connector *con,
>  static int ucsi_get_pdos(struct ucsi_connector *con, enum typec_role role,
>  			 int is_partner, u32 *pdos)
>  {
> +	struct ucsi *ucsi = con->ucsi;
>  	u8 num_pdos;
>  	int ret;
>  
> +	if (!(ucsi->cap.features & UCSI_CAP_PDO_DETAILS))
> +		return 0;
> +
>  	/* UCSI max payload means only getting at most 4 PDOs at a time */
>  	ret = ucsi_read_pdos(con, role, is_partner, pdos, 0, UCSI_MAX_PDOS);
>  	if (ret < 0)
> -- 
> 2.45.1

-- 
heikki