Commit af8b6270 authored by RD Babiera's avatar RD Babiera Committed by Greg Kroah-Hartman
Browse files

usb: typec: tcpm: add state machine support for SRC_VDM_IDENTITY_REQUEST 



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: default avatarRD Babiera <rdbabiera@google.com>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240108191620.987785-23-rdbabiera@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fb7ff25a

drivers/usb/typec/tcpm/tcpm.c

+43 −6
Original line number Diff line number Diff line
@@ -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),				\
@@ -1963,6 +1965,7 @@ 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;

				}
@@ -1994,6 +1997,16 @@ 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),
@@ -2288,7 +2301,8 @@ 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;

		}
@@ -2364,13 +2378,22 @@ 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;
@@ -4478,6 +4501,10 @@ static void run_state_machine(struct tcpm_port *port) 
		}

		ret = tcpm_pd_send_source_caps(port);

		if (ret < 0) {

			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 {
@@ -5395,6 +5422,15 @@ 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;
@@ -6120,7 +6156,8 @@ 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;

	}