Re: [PATCH v5 8/8] platform/chrome: cros_ec_typec: Disable tbt on port

[Benson Leung]

On Fri, Dec 13, 2024 at 03:35:49PM -0800, Abhishek Pandit-Subedi wrote:
> Altmodes with cros_ec are either automatically entered by the EC or
> entered by the AP if TBT or USB4 are supported on the system. Due to the
> security risk of PCIe tunneling, TBT modes should not be auto entered by
> the kernel at this time and will require user intervention.
> 
> With this change, a userspace program will need to explicitly activate
> the thunderbolt mode on the port and partner in order to enter the mode
> and the thunderbolt driver will not automatically enter when a partner
> is connected.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>

Reviewed-by: Benson Leung <bleung@xxxxxxxxxxxx>


> ---
> 
> (no changes since v3)
> 
> Changes in v3:
> - Set port.inactive = true instead of auto-enter.
> 
> Changes in v2:
> - Only disable auto-enter for Thunderbolt
> - Update commit message to clearly indicate the need for userspace
>   intervention to enter TBT mode
> 
>  drivers/platform/chrome/cros_ec_typec.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> index 1ac5798d887f..6ee182101bc9 100644
> --- a/drivers/platform/chrome/cros_ec_typec.c
> +++ b/drivers/platform/chrome/cros_ec_typec.c
> @@ -311,6 +311,7 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
>  		memset(&desc, 0, sizeof(desc));
>  		desc.svid = USB_TYPEC_TBT_SID;
>  		desc.mode = TBT_MODE;
> +		desc.inactive = true;
>  		amode = cros_typec_register_thunderbolt(port, &desc);
>  		if (IS_ERR(amode))
>  			return PTR_ERR(amode);
> -- 
> 2.47.1.613.gc27f4b7a9f-goog
>

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