Re: [PATCH 2/2] usb: typec: mux: avoid duplicated mux switches

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

Fri, Feb 13, 2026 at 08:23:29PM +0100, Sebastian Reichel wrote:
> Some devices use combo PHYs (i.e. USB3 + DisplayPort), which also
> handle the lane muxing. These PHYs are referenced twice from
> the USB-C connector (USB super-speed lines and SBU/AUX lines)
> resulting in the mux being configured twice. Avoid this by
> dropping duplicates.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
>  drivers/usb/typec/mux.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
> index db35b7398343..6a394326f236 100644
> --- a/drivers/usb/typec/mux.c
> +++ b/drivers/usb/typec/mux.c
> @@ -309,9 +309,9 @@ struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode)
>  {
>  	struct typec_mux_dev *mux_devs[TYPEC_MUX_MAX_DEVS];
>  	struct typec_mux *mux;
> +	int i, j, k;
>  	int count;
>  	int err;
> -	int i;
>  
>  	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
>  	if (!mux)
> @@ -333,6 +333,18 @@ struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode)
>  		}
>  	}
>  
> +	/* eliminate duplicates */
> +	for (i = 0; i < count; i++) {
> +		for (j = i + 1; j < count; j++) {
> +			if (mux_devs[j] == mux_devs[i]) {
> +				put_device(&mux_devs[j]->dev);
> +				for (k = j; k < count; k++)
> +					mux_devs[k] = mux_devs[k+1];
> +				count--;
> +			}
> +		}
> +	}

The same should work here. My code snippets probable has to be
modified, but the idea should work. The check should be more simple to
do in typec_switch_match().

Br,

-- 
heikki

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