On Mon, Aug 16, 2021 at 05:46:32PM +0200, Hans de Goede wrote:
> Commit a20dcf53ea98 ("usb: typec: tcpm: Respond Not_Supported if no
> snk_vdo"), stops tcpm_pd_data_request() calling tcpm_handle_vdm_request()
> when port->nr_snk_vdo is not set. But the VDM might be intended for an
> altmode-driver, in which case nr_snk_vdo does not matter.
>
> This change breaks the forwarding of connector hotplug (HPD) events
> for displayport altmode on devices which don't set nr_snk_vdo.
>
> tcpm_pd_data_request() is the only caller of tcpm_handle_vdm_request(),
> so we can move the nr_snk_vdo check to inside it, at which point we
> have already looked up the altmode device so we can check for this too.
>
> Doing this check here also ensures that vdm_state gets set to
> VDM_STATE_DONE if it was VDM_STATE_BUSY, even if we end up with
> responding with PD_MSG_CTRL_NOT_SUPP later.
>
> Note that tcpm_handle_vdm_request() was already sending
> PD_MSG_CTRL_NOT_SUPP in some circumstances, after moving the nr_snk_vdo
> check the same error-path is now taken when that check fails. So that
> we have only one error-path for this and not two. Replace the
> tcpm_queue_message(PD_MSG_CTRL_NOT_SUPP) used by the existing error-path
> with the more robust tcpm_pd_handle_msg() from the (now removed) second
> error-path.
>
> Cc: Kyle Tso <kyletso@xxxxxxxxxx>
> Fixes: a20dcf53ea98 ("usb: typec: tcpm: Respond Not_Supported if no snk_vdo")
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index b9bb63d749ec..f4079b5cb26d 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -1737,6 +1737,10 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
> return rlen;
> }
>
> +static void tcpm_pd_handle_msg(struct tcpm_port *port,
> + enum pd_msg_request message,
> + enum tcpm_ams ams);
> +
> static void tcpm_handle_vdm_request(struct tcpm_port *port,
> const __le32 *payload, int cnt)
> {
> @@ -1764,11 +1768,11 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
> port->vdm_state = VDM_STATE_DONE;
> }
>
> - if (PD_VDO_SVDM(p[0])) {
> + if (PD_VDO_SVDM(p[0]) && (adev || tcpm_vdm_ams(port) || port->nr_snk_vdo)) {
> rlen = tcpm_pd_svdm(port, adev, p, cnt, response, &adev_action);
> } else {
> if (port->negotiated_rev >= PD_REV30)
> - tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
> + tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
> }
>
> /*
> @@ -2471,10 +2475,7 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
> NONE_AMS);
> break;
> case PD_DATA_VENDOR_DEF:
> - if (tcpm_vdm_ams(port) || port->nr_snk_vdo)
> - tcpm_handle_vdm_request(port, msg->payload, cnt);
> - else if (port->negotiated_rev > PD_REV20)
> - tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
> + tcpm_handle_vdm_request(port, msg->payload, cnt);
> break;
> case PD_DATA_BIST:
> port->bist_request = le32_to_cpu(msg->payload[0]);
> --
> 2.31.1
--
heikki
