On Thu, Dec 14, 2023 at 11:08:53PM +0000, RD Babiera wrote:
> Add SRC_VDM_IDENTITY_REQUEST state which first enters after SRC_STARTUP.
> The state sends Discover Identity on SOP' and transitions to
> SRC_SEND_CAPABILITIES. SRC_SEND_CAPABILITIES will transition back into
> SRC_VDM_IDENTITY_REQUEST instead of retrying immediately.
>
> Signed-off-by: RD Babiera <rdbabiera@xxxxxxxxxx>
> ---
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> drivers/usb/typec/tcpm/tcpm.c | 49 ++++++++++++++++++++++++++++++-----
> 1 file changed, 43 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 5924e359e14d..e21bc2eea3fc 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -146,7 +146,9 @@
> S(PORT_RESET_WAIT_OFF), \
> \
> S(AMS_START), \
> - S(CHUNK_NOT_SUPP)
> + S(CHUNK_NOT_SUPP), \
> + \
> + S(SRC_VDM_IDENTITY_REQUEST)
>
> #define FOREACH_AMS(S) \
> S(NONE_AMS), \
> @@ -1956,6 +1958,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
> ret = tcpm_ams_start(port, VCONN_SWAP);
> if (!ret)
> return 0;
> + /* Cannot perform Vconn swap */
> port->upcoming_state = INVALID_STATE;
> port->send_discover_prime = false;
> }
> @@ -1987,6 +1990,16 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
> * the svdm_version for the cable moving forward.
> */
> svdm_consume_identity_sop_prime(port, p, cnt);
> +
> + /*
> + * If received in SRC_VDM_IDENTITY_REQUEST, continue
> + * to SRC_SEND_CAPABILITIES
> + */
> + if (port->state == SRC_VDM_IDENTITY_REQUEST) {
> + tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
> + return 0;
> + }
> +
> *response_tx_sop_type = TCPC_TX_SOP;
> response[0] = VDO(USB_SID_PD, 1,
> typec_get_negotiated_svdm_version(typec),
> @@ -2281,7 +2294,8 @@ static void vdm_run_state_machine(struct tcpm_port *port)
> * if there's traffic or we're not in PDO ready state don't send
> * a VDM.
> */
> - if (port->state != SRC_READY && port->state != SNK_READY) {
> + if (port->state != SRC_READY && port->state != SNK_READY &&
> + port->state != SRC_VDM_IDENTITY_REQUEST) {
> port->vdm_sm_running = false;
> break;
> }
> @@ -2357,13 +2371,22 @@ static void vdm_run_state_machine(struct tcpm_port *port)
> tcpm_ams_finish(port);
> break;
> case VDM_STATE_ERR_SEND:
> + /*
> + * When sending Discover Identity to SOP' before establishing an
> + * explicit contract, do not retry. Instead, weave sending
> + * Source_Capabilities over SOP and Discover Identity over SOP'.
> + */
> + if (port->state == SRC_VDM_IDENTITY_REQUEST) {
> + tcpm_ams_finish(port);
> + port->vdm_state = VDM_STATE_DONE;
> + tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
> /*
> * A partner which does not support USB PD will not reply,
> * so this is not a fatal error. At the same time, some
> * devices may not return GoodCRC under some circumstances,
> * so we need to retry.
> */
> - if (port->vdm_retries < 3) {
> + } else if (port->vdm_retries < 3) {
> tcpm_log(port, "VDM Tx error, retry");
> port->vdm_retries++;
> port->vdm_state = VDM_STATE_READY;
> @@ -4477,8 +4500,12 @@ static void run_state_machine(struct tcpm_port *port)
> }
> ret = tcpm_pd_send_source_caps(port);
> if (ret < 0) {
> - tcpm_set_state(port, SRC_SEND_CAPABILITIES,
> - PD_T_SEND_SOURCE_CAP);
> + if (tcpm_can_communicate_sop_prime(port) &&
> + IS_ERR_OR_NULL(port->cable))
> + tcpm_set_state(port, SRC_VDM_IDENTITY_REQUEST, 0);
> + else
> + tcpm_set_state(port, SRC_SEND_CAPABILITIES,
> + PD_T_SEND_SOURCE_CAP);
> } else {
> /*
> * Per standard, we should clear the reset counter here.
> @@ -5393,6 +5420,15 @@ static void run_state_machine(struct tcpm_port *port)
> tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP, TCPC_TX_SOP);
> tcpm_set_state(port, port->pwr_role == TYPEC_SOURCE ? SRC_READY : SNK_READY, 0);
> break;
> +
> + /* Cable states */
> + case SRC_VDM_IDENTITY_REQUEST:
> + port->send_discover_prime = true;
> + port->tx_sop_type = TCPC_TX_SOP_PRIME;
> + mod_send_discover_delayed_work(port, 0);
> + port->upcoming_state = SRC_SEND_CAPABILITIES;
> + break;
> +
> default:
> WARN(1, "Unexpected port state %d\n", port->state);
> break;
> @@ -6118,7 +6154,8 @@ static void tcpm_send_discover_work(struct kthread_work *work)
> }
>
> /* Retry if the port is not idle */
> - if ((port->state != SRC_READY && port->state != SNK_READY) || port->vdm_sm_running) {
> + if ((port->state != SRC_READY && port->state != SNK_READY &&
> + port->state != SRC_VDM_IDENTITY_REQUEST) || port->vdm_sm_running) {
> mod_send_discover_delayed_work(port, SEND_DISCOVER_RETRY_MS);
> goto unlock;
> }
> --
> 2.43.0.472.g3155946c3a-goog
--
heikki
