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From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: RD Babiera <rdbabiera@google.com>
Cc: gregkh@linuxfoundation.org, badhri@google.com,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] usb: typec: altmodes/displayport: do not enter mode if port is the UFP
Date: Wed, 8 Oct 2025 13:33:28 +0300	[thread overview]
Message-ID: <aOY9-B1V3SNvcjrF@kuha.fi.intel.com> (raw)
In-Reply-To: <20250923181606.1583584-6-rdbabiera@google.com>

On Tue, Sep 23, 2025 at 06:16:08PM +0000, RD Babiera wrote:
> Nothing currently stops the DisplayPort Alt Mode driver from sending
> Enter Mode if the port is the Data Device. Utilize
> typec_altmode_get_data_role to prevent mode entry.
> 
> Signed-off-by: RD Babiera <rdbabiera@google.com>

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

> ---
>  drivers/usb/typec/altmodes/displayport.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index 1dcb77faf85d..8d111ad3b71b 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -758,7 +758,9 @@ int dp_altmode_probe(struct typec_altmode *alt)
>  	struct fwnode_handle *fwnode;
>  	struct dp_altmode *dp;
>  
> -	/* FIXME: Port can only be DFP_U. */
> +	/* Port can only be DFP_U. */
> +	if (typec_altmode_get_data_role(alt) != TYPEC_HOST)
> +		return -EPROTO;
>  
>  	/* Make sure we have compatible pin configurations */
>  	if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
> -- 
> 2.51.0.534.gc79095c0ca-goog

-- 
heikki

  reply	other threads:[~2025-10-08 10:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-23 18:16 [PATCH v2 0/2] usb: typec: altmodes/displayport: add port data role handling support RD Babiera
2025-09-23 18:16 ` [PATCH v2 1/2] usb: typec: class: add typec_get_data_role symbol RD Babiera
2025-10-08 10:32   ` Heikki Krogerus
2025-09-23 18:16 ` [PATCH v2 2/2] usb: typec: altmodes/displayport: do not enter mode if port is the UFP RD Babiera
2025-10-08 10:33   ` Heikki Krogerus [this message]
2026-01-10  7:53   ` Andy Yan

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