Re: [PATCH] usb: typec: ucsi: displayport: Current CAM OOB index fixup

[Heikki Krogerus]

On Fri, Sep 11, 2026 at 07:32:08PM +0000, Jameson Thies wrote:
> Update ucsi_displayport_enter() to return invalid error when the PPM
> reports an current alternate mode greater than or equal to
> UCSI_MAX_ALTMODES. While here, remove 0xff current cam assignment on
> failed GET_CURRENT_CAM response.
> 
> Signed-off-by: Jameson Thies <jthies@xxxxxxxxxx>

Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

> ---
> Original patch didn't incorporate reviewer feedback. This is a fixup
> to be amended to:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=04cec690b1fd9d1c4c314b91a10d8c68a3acfe18
> 
>  drivers/usb/typec/ucsi/displayport.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c
> index 8d2032d0762c..572da7bbd29c 100644
> --- a/drivers/usb/typec/ucsi/displayport.c
> +++ b/drivers/usb/typec/ucsi/displayport.c
> @@ -71,11 +71,14 @@ static int ucsi_displayport_enter(struct typec_altmode *alt, u32 *vdo)
>  	if (ret < 0) {
>  		if (ucsi->version > 0x0100)
>  			goto err_unlock;
> -		cur = 0xff;
>  	}
>  
> -	if (cur < UCSI_MAX_ALTMODES) {
> -		ret = dp->con->port_altmode[cur] == alt ? 0 : -EBUSY;
> +	if (cur != 0xff) {
> +		if (cur < UCSI_MAX_ALTMODES)
> +			ret = dp->con->port_altmode[cur] == alt ? 0 : -EBUSY;
> +		else
> +			ret = -EINVAL;
> +
>  		goto err_unlock;
>  	}
>  
> 
> base-commit: ed2050bc671b44b2c948dbd4347cc534d44ccc9f
> -- 
> 2.55.0.1007.g17ff1f9808-goog

-- 
heikki