* [PATCH v1] usb: typec: tcpm: implement retry mechanism for Discover Identity VDMs
@ 2026-06-15 19:49 RD Babiera
0 siblings, 0 replies; only message in thread
From: RD Babiera @ 2026-06-15 19:49 UTC (permalink / raw)
Cc: badhri, heikki.krogerus, gregkh, linux-usb, linux-kernel,
RD Babiera
The current mechanism for sending Discover Identity in the ready state
presents a flaw where tcpm_queue_vdm can collide with non interruptible
AMSes such as GET_SINK_CAP or VCONN_SWAP. vdm_run_state_machine will hit
the VDM_STATE_BUSY state, and Discover SVIDs or Discover Modes will not
retry.
This patch introduces a state machine under the enum vdm_discovery_states.
The tcpm_port field vdm_discover_state tracks which step of the Discover
Identity process has been completed.
The current TCPM implementation utilizes the send_discover and
send_discover_prime booleans to queue Discover Identity in the
aforementioned collision case. These booleans are removed in place of
vdm_discover_state and send_discover_work is replaced by
vdm_discovery_work, which runs unconditionally in the ready state.
When the Discovery process is complete, the port will move to the
VDM_DISCOVERY_COMPLETE state and vdm_discovery_work becomes a no-op.
When there are still Discovery VDMs to be sent, vdm_discovery_work will
continue based on the last received response from the port partner or
cable.
Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
---
drivers/usb/typec/tcpm/tcpm.c | 417 ++++++++++++++++++++++------------
1 file changed, 275 insertions(+), 142 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 7ef746a90a17..3d16e4b41108 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -212,6 +212,88 @@ static const char * const tcpm_ams_str[] = {
FOREACH_AMS(GENERATE_STRING)
};
+enum vdm_discovery_states {
+ /*
+ * VDM_DISCOVERY_UNKNOWN: The port has not received a Discover Identity response
+ * from the port partner.
+ *
+ * 1. The port will send Discover Identity to the partner over SOP in the SRC_READY
+ * and SNK_READY states if there is an explicit contract.
+ * 2. The port will send Discover Identity to the cable over SOP' in the
+ * SRC_VDM_IDENTITY_REQUEST state if capable of doing so.
+ */
+ VDM_DISCOVERY_UNKNOWN = 0,
+ /*
+ * VDM_DISCOVERY_PARTNER_IDENT: The port has received a Discover Identity ACK
+ * from the port partner.
+ *
+ * 1. The port will send Discover Identity to the cable over SOP' in the SRC_READY and
+ * SNK_READY states if it did not previously discover the cable but is capable of doing
+ * so.
+ * 2. The port will send Discover SVIDs to the partner over SOP in the SRC_READY and
+ * SNK_READY states otherwise.
+ */
+ VDM_DISCOVERY_PARTNER_IDENT,
+ /*
+ * VDM_DISCOVERY_CABLE_IDENT: The port has received a Discover Identity ACK
+ * from the cable.
+ *
+ * 1. The port will send Discover SVIDs to the partner over SOP.
+ */
+ VDM_DISCOVERY_CABLE_IDENT,
+ /*
+ * VDM_DISCOVERY_PARTNER_SVIDS: The port has received a Discover SVIDs ACK from the partner
+ * for the last SVIDs supported by the partner.
+ *
+ * 1. The port will send Discover Modes for the first SVID over SOP if the partner supports
+ * modal operation and valid SVIDs were registered.
+ * 2. The vdm_discovery_state will move to VDM_DISCOVERY_COMPLETE otherwise.
+ */
+ VDM_DISCOVERY_PARTNER_SVIDS,
+ /*
+ * VDM_DISCOVERY_PARTNER_MODES: The port has received a Discover Modes ACK from the partner
+ * for any mode.
+ *
+ * 1. The port will send Discover Modes for the next SVID that has not been discovered to
+ * the port partner over SOP.
+ * 2. The port will send Discover SVIDs over SOP' if the port can communicate over SOP'
+ * and the cable supports VDMs.
+ * 3. The vdm_discovery_state will move to VDM_DISCOVERY_COMPLETE otherwise.
+ */
+ VDM_DISCOVERY_PARTNER_MODES,
+ /*
+ * VDM_DISCOVERY_CABLE_SVIDS: The port has received a Discover SVIDs ACK from the cable over
+ * SOP'.
+ *
+ * 1. The port will send Discover Modes for the first SVID over SOP'.
+ */
+ VDM_DISCOVERY_CABLE_SVIDS,
+ /*
+ * VDM_DISCOVERY_CABLE_MODES: The port has received a Discover Modes ACK from the cable for
+ * any mode.
+ *
+ * 1. The port will send Discover Modes for the next SVID that has not been discovered to
+ * the cable over SOP'.
+ */
+ VDM_DISCOVERY_CABLE_MODES,
+ /*
+ * VDM_DISCOVERY_COMPLETE: The port partner does not need to send a Discovery VDM to the
+ * port partner or cable.
+ */
+ VDM_DISCOVERY_COMPLETE,
+};
+
+const char *vdm_discovery_state_strings[] = {
+ [VDM_DISCOVERY_UNKNOWN] = "VDM_DISCOVERY_UNKNOWN",
+ [VDM_DISCOVERY_PARTNER_IDENT] = "VDM_DISCOVERY_PARTNER_IDENT",
+ [VDM_DISCOVERY_CABLE_IDENT] = "VDM_DISCOVERY_CABLE_IDENT",
+ [VDM_DISCOVERY_PARTNER_SVIDS] = "VDM_DISCOVERY_PARTNER_SVIDS",
+ [VDM_DISCOVERY_PARTNER_MODES] = "VDM_DISCOVERY_PARTNER_MODES",
+ [VDM_DISCOVERY_CABLE_SVIDS] = "VDM_DISCOVERY_CABLE_SVIDS",
+ [VDM_DISCOVERY_CABLE_MODES] = "VDM_DISCOVERY_CABLE_MODES",
+ [VDM_DISCOVERY_COMPLETE] = "VDM_DISCOVERY_COMPLETE",
+};
+
enum vdm_states {
VDM_STATE_ERR_BUSY = -3,
VDM_STATE_ERR_SEND = -2,
@@ -274,7 +356,7 @@ enum frs_typec_current {
#define ALTMODE_DISCOVERY_MAX (SVID_DISCOVERY_MAX * MODE_DISCOVERY_MAX)
#define GET_SINK_CAP_RETRY_MS 100
-#define SEND_DISCOVER_RETRY_MS 100
+#define SEND_DISCOVERY_VDM_RETRY_MS 100
struct pd_mode_data {
int svid_index; /* current SVID index */
@@ -483,8 +565,6 @@ struct tcpm_port {
bool vbus_source;
bool vbus_charge;
- /* Set to true when Discover_Identity Command is expected to be sent in Ready states. */
- bool send_discover;
bool op_vsafe5v;
int try_role;
@@ -510,8 +590,8 @@ struct tcpm_port {
struct kthread_work vdm_state_machine;
struct hrtimer enable_frs_timer;
struct kthread_work enable_frs;
- struct hrtimer send_discover_timer;
- struct kthread_work send_discover_work;
+ struct hrtimer vdm_discovery_timer;
+ struct kthread_work vdm_discovery_work;
bool state_machine_running;
/* Set to true when VDM State Machine has following actions. */
bool vdm_sm_running;
@@ -578,6 +658,9 @@ struct tcpm_port {
u32 bist_request;
+ /* VDM Discovery State to determine message sent */
+ enum vdm_discovery_states vdm_discovery_state;
+
/* PD state for Vendor Defined Messages */
enum vdm_states vdm_state;
u32 vdm_retries;
@@ -641,12 +724,6 @@ struct tcpm_port {
bool potential_contaminant;
/* SOP* Related Fields */
- /*
- * Flag to determine if SOP' Discover Identity is available. The flag
- * is set if Discover Identity on SOP' does not immediately follow
- * Discover Identity on SOP.
- */
- bool send_discover_prime;
/*
* tx_sop_type determines which SOP* a message is being sent on.
* For messages that are queued and not sent immediately such as in
@@ -771,6 +848,9 @@ static const char * const pd_rev[] = {
#define tcpm_wait_for_discharge(port) \
(((port)->auto_vbus_discharge_enabled && !(port)->vbus_vsafe0v) ? PD_T_SAFE_0V : 0)
+#define tcpm_can_send_vdm(state) \
+ ((state == SRC_READY || state == SNK_READY || state == SRC_VDM_IDENTITY_REQUEST))
+
static enum tcpm_state tcpm_default_state(struct tcpm_port *port)
{
if (port->port_type == TYPEC_PORT_DRP) {
@@ -1559,13 +1639,19 @@ static void mod_enable_frs_delayed_work(struct tcpm_port *port, unsigned int del
}
}
-static void mod_send_discover_delayed_work(struct tcpm_port *port, unsigned int delay_ms)
+static void mod_vdm_discovery_cancel_delayed_work(struct tcpm_port *port)
+{
+ hrtimer_cancel(&port->vdm_discovery_timer);
+ kthread_cancel_work_sync(&port->vdm_discovery_work);
+}
+
+static void mod_vdm_discovery_delayed_work(struct tcpm_port *port, unsigned int delay_ms)
{
if (delay_ms) {
- hrtimer_start(&port->send_discover_timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
+ hrtimer_start(&port->vdm_discovery_timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
} else {
- hrtimer_cancel(&port->send_discover_timer);
- kthread_queue_work(port->wq, &port->send_discover_work);
+ hrtimer_cancel(&port->vdm_discovery_timer);
+ kthread_queue_work(port->wq, &port->vdm_discovery_work);
}
}
@@ -1773,16 +1859,11 @@ static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header,
WARN_ON(!mutex_is_locked(&port->lock));
/* If is sending discover_identity, handle received message first */
- if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMD(vdo_hdr) == CMD_DISCOVER_IDENT) {
- if (tx_sop_type == TCPC_TX_SOP_PRIME)
- port->send_discover_prime = true;
- else
- port->send_discover = true;
- mod_send_discover_delayed_work(port, SEND_DISCOVER_RETRY_MS);
- } else {
+ if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMD(vdo_hdr) == CMD_DISCOVER_IDENT)
+ mod_vdm_discovery_delayed_work(port, SEND_DISCOVERY_VDM_RETRY_MS);
+ else
/* Make sure we are not still processing a previous VDM packet */
WARN_ON(port->vdm_state > VDM_STATE_DONE);
- }
port->vdo_count = cnt + 1;
port->vdo_data[0] = header;
@@ -1805,8 +1886,7 @@ static void tcpm_queue_vdm_work(struct kthread_work *work)
struct tcpm_port *port = event->port;
mutex_lock(&port->lock);
- if (port->state != SRC_READY && port->state != SNK_READY &&
- port->state != SRC_VDM_IDENTITY_REQUEST) {
+ if (!tcpm_can_send_vdm(port->state)) {
tcpm_log_force(port, "dropping altmode_vdm_event");
goto port_unlock;
}
@@ -2149,6 +2229,19 @@ static bool tcpm_cable_vdm_supported(struct tcpm_port *port)
tcpm_can_communicate_sop_prime(port);
}
+static void tcpm_update_vdm_discovery_state(struct tcpm_port *port,
+ enum vdm_discovery_states new_state)
+{
+ enum vdm_discovery_states old_state = port->vdm_discovery_state;
+
+ if (old_state != new_state)
+ tcpm_log_force(port, "vdm discovery state changed [%s -> %s]",
+ vdm_discovery_state_strings[old_state],
+ vdm_discovery_state_strings[new_state]);
+
+ port->vdm_discovery_state = new_state;
+}
+
static int tcpm_handle_discover_mode(struct tcpm_port *port, u32 *response,
enum tcpm_transmit_type rx_sop_type,
enum tcpm_transmit_type *response_tx_sop_type)
@@ -2166,6 +2259,7 @@ static int tcpm_handle_discover_mode(struct tcpm_port *port, u32 *response,
response[0] = VDO(svid, 1,
typec_get_negotiated_svdm_version(typec),
CMD_DISCOVER_MODES);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_PARTNER_MODES);
return 1;
}
@@ -2174,10 +2268,12 @@ static int tcpm_handle_discover_mode(struct tcpm_port *port, u32 *response,
response[0] = VDO(USB_SID_PD, 1,
typec_get_cable_svdm_version(typec),
CMD_DISCOVER_SVID);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_PARTNER_MODES);
return 1;
}
tcpm_register_partner_altmodes(port);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
} else if (rx_sop_type == TCPC_TX_SOP_PRIME) {
modep = &port->mode_data_prime;
modep->svid_index++;
@@ -2188,11 +2284,13 @@ static int tcpm_handle_discover_mode(struct tcpm_port *port, u32 *response,
response[0] = VDO(svid, 1,
typec_get_cable_svdm_version(typec),
CMD_DISCOVER_MODES);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_CABLE_MODES);
return 1;
}
tcpm_register_plug_altmodes(port);
tcpm_register_partner_altmodes(port);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
}
return 0;
@@ -2371,18 +2469,18 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
typec_cable_set_svdm_version(port->cable,
svdm_version);
}
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_PARTNER_IDENT);
+
/* 6.4.4.3.1 */
svdm_consume_identity(port, p, cnt);
/* Attempt Vconn swap, delay SOP' discovery if necessary */
if (tcpm_attempt_vconn_swap_discovery(port)) {
- port->send_discover_prime = true;
port->upcoming_state = VCONN_SWAP_SEND;
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;
}
/*
@@ -2393,7 +2491,6 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
if (IS_ERR_OR_NULL(port->cable) &&
tcpm_can_communicate_sop_prime(port)) {
*response_tx_sop_type = TCPC_TX_SOP_PRIME;
- port->send_discover_prime = true;
response[0] = VDO(USB_SID_PD, 1,
typec_get_negotiated_svdm_version(typec),
CMD_DISCOVER_IDENT);
@@ -2421,6 +2518,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
return 0;
}
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_CABLE_IDENT);
*response_tx_sop_type = TCPC_TX_SOP;
response[0] = VDO(USB_SID_PD, 1,
@@ -2440,16 +2538,27 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
rlen = 1;
} else {
if (rx_sop_type == TCPC_TX_SOP) {
+ tcpm_update_vdm_discovery_state(port,
+ VDM_DISCOVERY_PARTNER_SVIDS);
if (modep->nsvids && supports_modal(port)) {
response[0] = VDO(modep->svids[0], 1, svdm_version,
CMD_DISCOVER_MODES);
rlen = 1;
+ } else {
+ tcpm_update_vdm_discovery_state(port,
+ VDM_DISCOVERY_COMPLETE);
}
} else if (rx_sop_type == TCPC_TX_SOP_PRIME) {
+ tcpm_update_vdm_discovery_state(port,
+ VDM_DISCOVERY_CABLE_SVIDS);
if (modep_prime->nsvids) {
response[0] = VDO(modep_prime->svids[0], 1,
svdm_version, CMD_DISCOVER_MODES);
rlen = 1;
+ } else {
+ tcpm_register_partner_altmodes(port);
+ tcpm_update_vdm_discovery_state(port,
+ VDM_DISCOVERY_COMPLETE);
}
}
}
@@ -2500,8 +2609,13 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
case CMDT_RSP_NAK:
tcpm_ams_finish(port);
switch (cmd) {
+ /*
+ * The cable is not allowed to respond with NAK so this must've happened over SOP
+ */
case CMD_DISCOVER_IDENT:
case CMD_DISCOVER_SVID:
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
+ break;
case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
break;
case CMD_DISCOVER_MODES:
@@ -2681,44 +2795,6 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
port->vdm_sm_running = false;
}
-static void tcpm_send_vdm(struct tcpm_port *port, u32 vid, int cmd,
- const u32 *data, int count, enum tcpm_transmit_type tx_sop_type)
-{
- int svdm_version;
- u32 header;
-
- switch (tx_sop_type) {
- case TCPC_TX_SOP_PRIME:
- /*
- * If the port partner is discovered, then the port partner's
- * SVDM Version will be returned
- */
- svdm_version = typec_get_cable_svdm_version(port->typec_port);
- if (svdm_version < 0)
- svdm_version = SVDM_VER_MAX;
- break;
- case TCPC_TX_SOP:
- svdm_version = typec_get_negotiated_svdm_version(port->typec_port);
- if (svdm_version < 0)
- return;
- break;
- default:
- svdm_version = typec_get_negotiated_svdm_version(port->typec_port);
- if (svdm_version < 0)
- return;
- break;
- }
-
- if (WARN_ON(count > VDO_MAX_SIZE - 1))
- count = VDO_MAX_SIZE - 1;
-
- /* set VDM header with VID & CMD */
- header = VDO(vid, ((vid & USB_SID_PD) == USB_SID_PD) ?
- 1 : (PD_VDO_CMD(cmd) <= CMD_ATTENTION),
- svdm_version, cmd);
- tcpm_queue_vdm(port, header, data, count, tx_sop_type);
-}
-
static unsigned int vdm_ready_timeout(u32 vdm_hdr)
{
unsigned int timeout;
@@ -2764,8 +2840,7 @@ 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 &&
- port->state != SRC_VDM_IDENTITY_REQUEST) {
+ if (!tcpm_can_send_vdm(port->state)) {
port->vdm_sm_running = false;
break;
}
@@ -2775,22 +2850,10 @@ static void vdm_run_state_machine(struct tcpm_port *port)
switch (PD_VDO_CMD(vdo_hdr)) {
case CMD_DISCOVER_IDENT:
res = tcpm_ams_start(port, DISCOVER_IDENTITY);
- if (res == 0) {
- switch (port->tx_sop_type) {
- case TCPC_TX_SOP_PRIME:
- port->send_discover_prime = false;
- break;
- case TCPC_TX_SOP:
- port->send_discover = false;
- break;
- default:
- port->send_discover = false;
- break;
- }
- } else if (res == -EAGAIN) {
+ if (res == -EAGAIN) {
port->vdo_data[0] = 0;
- mod_send_discover_delayed_work(port,
- SEND_DISCOVER_RETRY_MS);
+ mod_vdm_discovery_delayed_work(port,
+ SEND_DISCOVERY_VDM_RETRY_MS);
}
break;
case CMD_DISCOVER_SVID:
@@ -2848,6 +2911,7 @@ static void vdm_run_state_machine(struct tcpm_port *port)
*/
if (port->state == SRC_VDM_IDENTITY_REQUEST) {
tcpm_ams_finish(port);
+ port->vdo_data[0] = 0;
port->vdm_state = VDM_STATE_DONE;
tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
/*
@@ -2864,6 +2928,7 @@ static void vdm_run_state_machine(struct tcpm_port *port)
tcpm_ams_finish(port);
} else {
tcpm_ams_finish(port);
+ port->vdo_data[0] = 0;
if (port->tx_sop_type == TCPC_TX_SOP)
break;
/* Handle SOP' Transmission Errors */
@@ -2873,11 +2938,11 @@ static void vdm_run_state_machine(struct tcpm_port *port)
* discovery process on SOP only.
*/
case CMD_DISCOVER_IDENT:
- port->vdo_data[0] = 0;
response[0] = VDO(USB_SID_PD, 1,
typec_get_negotiated_svdm_version(
port->typec_port),
CMD_DISCOVER_SVID);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_CABLE_IDENT);
tcpm_queue_vdm(port, response[0], &response[1],
0, TCPC_TX_SOP);
break;
@@ -2887,9 +2952,11 @@ static void vdm_run_state_machine(struct tcpm_port *port)
*/
case CMD_DISCOVER_SVID:
tcpm_register_partner_altmodes(port);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
break;
case CMD_DISCOVER_MODES:
tcpm_register_partner_altmodes(port);
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
break;
default:
break;
@@ -3802,7 +3869,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
PD_MSG_CTRL_NOT_SUPP,
NONE_AMS);
} else {
- if (port->send_discover && port->negotiated_rev < PD_REV30) {
+ if (port->vdm_discovery_state == VDM_DISCOVERY_UNKNOWN &&
+ port->negotiated_rev < PD_REV30) {
tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
break;
}
@@ -3818,7 +3886,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
PD_MSG_CTRL_NOT_SUPP,
NONE_AMS);
} else {
- if (port->send_discover && port->negotiated_rev < PD_REV30) {
+ if (port->vdm_discovery_state == VDM_DISCOVERY_UNKNOWN &&
+ port->negotiated_rev < PD_REV30) {
tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
break;
}
@@ -3827,7 +3896,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
}
break;
case PD_CTRL_VCONN_SWAP:
- if (port->send_discover && port->negotiated_rev < PD_REV30) {
+ if (port->vdm_discovery_state == VDM_DISCOVERY_UNKNOWN &&
+ port->negotiated_rev < PD_REV30) {
tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
break;
}
@@ -4848,8 +4918,7 @@ static int tcpm_src_attach(struct tcpm_port *port)
port->partner = NULL;
port->attached = true;
- port->send_discover = true;
- port->send_discover_prime = false;
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_UNKNOWN);
return 0;
@@ -4926,6 +4995,7 @@ static void tcpm_reset_port(struct tcpm_port *port)
port->in_ams = false;
port->ams = NONE_AMS;
port->vdm_sm_running = false;
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
tcpm_unregister_altmodes(port);
tcpm_typec_disconnect(port);
port->attached = false;
@@ -5009,8 +5079,7 @@ static int tcpm_snk_attach(struct tcpm_port *port)
port->partner = NULL;
port->attached = true;
- port->send_discover = true;
- port->send_discover_prime = false;
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_UNKNOWN);
return 0;
}
@@ -5417,16 +5486,11 @@ static void run_state_machine(struct tcpm_port *port)
* as well.
*/
if (port->explicit_contract) {
- if (port->send_discover_prime) {
- port->tx_sop_type = TCPC_TX_SOP_PRIME;
- } else {
- port->tx_sop_type = TCPC_TX_SOP;
+ if (port->vdm_discovery_state == VDM_DISCOVERY_UNKNOWN)
tcpm_set_initial_svdm_version(port);
- }
- mod_send_discover_delayed_work(port, 0);
+ mod_vdm_discovery_delayed_work(port, 0);
} else {
- port->send_discover = false;
- port->send_discover_prime = false;
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
}
/*
@@ -5809,18 +5873,14 @@ static void run_state_machine(struct tcpm_port *port)
* as well.
*/
if (port->explicit_contract) {
- if (port->send_discover_prime) {
- port->tx_sop_type = TCPC_TX_SOP_PRIME;
- } else {
- port->tx_sop_type = TCPC_TX_SOP;
+ if (port->vdm_discovery_state == VDM_DISCOVERY_UNKNOWN)
tcpm_set_initial_svdm_version(port);
- }
- mod_send_discover_delayed_work(port, 0);
+ mod_vdm_discovery_delayed_work(port, 0);
} else {
- port->send_discover = false;
- port->send_discover_prime = false;
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
}
+
power_supply_changed(port->psy);
break;
@@ -5864,8 +5924,8 @@ static void run_state_machine(struct tcpm_port *port)
port->tcpc->set_pd_rx(port->tcpc, false);
tcpm_unregister_altmodes(port);
port->nr_sink_caps = 0;
- port->send_discover = true;
- port->send_discover_prime = false;
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_UNKNOWN);
+ mod_vdm_discovery_cancel_delayed_work(port);
if (port->pwr_role == TYPEC_SOURCE)
tcpm_set_state(port, SRC_HARD_RESET_VBUS_OFF,
PD_T_PS_HARD_RESET);
@@ -6012,25 +6072,15 @@ static void run_state_machine(struct tcpm_port *port)
/* DR_Swap states */
case DR_SWAP_SEND:
tcpm_pd_send_control(port, PD_CTRL_DR_SWAP, TCPC_TX_SOP);
- if (port->data_role == TYPEC_DEVICE || port->negotiated_rev > PD_REV20) {
- port->send_discover = true;
- port->send_discover_prime = false;
- }
tcpm_set_state_cond(port, DR_SWAP_SEND_TIMEOUT,
PD_T_SENDER_RESPONSE);
break;
case DR_SWAP_ACCEPT:
tcpm_pd_send_control(port, PD_CTRL_ACCEPT, TCPC_TX_SOP);
- if (port->data_role == TYPEC_DEVICE || port->negotiated_rev > PD_REV20) {
- port->send_discover = true;
- port->send_discover_prime = false;
- }
tcpm_set_state_cond(port, DR_SWAP_CHANGE_DR, 0);
break;
case DR_SWAP_SEND_TIMEOUT:
tcpm_swap_complete(port, -ETIMEDOUT);
- port->send_discover = false;
- port->send_discover_prime = false;
tcpm_ams_finish(port);
tcpm_set_state(port, ready_state(port), 0);
break;
@@ -6042,6 +6092,8 @@ static void run_state_machine(struct tcpm_port *port)
else
tcpm_set_roles(port, true, TYPEC_STATE_USB, port->pwr_role,
TYPEC_HOST);
+ if (port->data_role == TYPEC_HOST || port->negotiated_rev > PD_REV20)
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_UNKNOWN);
tcpm_ams_finish(port);
tcpm_set_state(port, ready_state(port), 0);
break;
@@ -6325,9 +6377,7 @@ static void run_state_machine(struct tcpm_port *port)
/* 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);
+ mod_vdm_discovery_delayed_work(port, 0);
port->upcoming_state = SRC_SEND_CAPABILITIES;
break;
@@ -7031,8 +7081,8 @@ static void tcpm_enable_frs_work(struct kthread_work *work)
goto unlock;
/* Send when the state machine is idle */
- if (port->state != SNK_READY || port->vdm_sm_running || port->send_discover ||
- port->send_discover_prime)
+ if (port->state != SNK_READY || port->vdm_sm_running ||
+ port->vdm_discovery_state == VDM_DISCOVERY_UNKNOWN)
goto resched;
port->upcoming_state = GET_SINK_CAP;
@@ -7049,30 +7099,113 @@ static void tcpm_enable_frs_work(struct kthread_work *work)
mutex_unlock(&port->lock);
}
-static void tcpm_send_discover_work(struct kthread_work *work)
+static void tcpm_vdm_discovery_work(struct kthread_work *work)
{
- struct tcpm_port *port = container_of(work, struct tcpm_port, send_discover_work);
+ struct tcpm_port *port = container_of(work, struct tcpm_port, vdm_discovery_work);
+ enum tcpm_transmit_type tx_sop_type = TCPC_TX_SOP;
+ struct typec_port *typec = port->typec_port;
+ struct pd_mode_data *modep, *modep_prime;
+ u32 msg[2] = { };
+ int svdm_version;
mutex_lock(&port->lock);
- /* No need to send DISCOVER_IDENTITY anymore */
- if (!port->send_discover && !port->send_discover_prime)
+
+ tcpm_log_force(port, "%s state [%s]", __func__,
+ vdm_discovery_state_strings[port->vdm_discovery_state]);
+
+ /* No need to perform work if Discovery process is complete */
+ if (port->vdm_discovery_state == VDM_DISCOVERY_COMPLETE)
goto unlock;
- if (port->data_role == TYPEC_DEVICE && port->negotiated_rev < PD_REV30) {
- port->send_discover = false;
- port->send_discover_prime = false;
+ /* Retry if the port is not idle */
+ if (!tcpm_can_send_vdm(port->state) || port->vdm_sm_running) {
+ mod_vdm_discovery_delayed_work(port, SEND_DISCOVERY_VDM_RETRY_MS);
goto unlock;
}
- /* Retry if the port is not idle */
- 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);
+ modep = &port->mode_data;
+ modep_prime = &port->mode_data_prime;
+
+ svdm_version = typec_get_negotiated_svdm_version(typec);
+
+ switch (port->vdm_discovery_state) {
+ case VDM_DISCOVERY_UNKNOWN:
+ /* Can't send Discover Identity, VDM discovery is complete */
+ if (port->data_role == TYPEC_DEVICE && port->negotiated_rev < PD_REV30) {
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
+ goto unlock;
+ }
+
+ if (port->state == SRC_VDM_IDENTITY_REQUEST) {
+ tx_sop_type = TCPC_TX_SOP_PRIME;
+ svdm_version = SVDM_VER_MAX;
+ }
+
+ msg[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_IDENT);
+ break;
+ case VDM_DISCOVERY_PARTNER_IDENT:
+ if (tcpm_can_communicate_sop_prime(port) && !port->cable) {
+ tx_sop_type = TCPC_TX_SOP_PRIME;
+ msg[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_IDENT);
+ } else {
+ if (tcpm_can_communicate_sop_prime(port))
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_CABLE_IDENT);
+ msg[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_SVID);
+ }
+ break;
+ case VDM_DISCOVERY_CABLE_IDENT:
+ msg[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_SVID);
+ break;
+ case VDM_DISCOVERY_PARTNER_SVIDS:
+ if (modep->nsvids && supports_modal(port)) {
+ msg[0] = VDO(modep->svids[0], 1, svdm_version, CMD_DISCOVER_MODES);
+ } else {
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
+ goto unlock;
+ }
+ break;
+ case VDM_DISCOVERY_PARTNER_MODES:
+ /* Not all modes have been discovered yet */
+ if (modep->svid_index < modep->nsvids) {
+ msg[0] = VDO(modep_prime->svids[modep->svid_index], 1, svdm_version,
+ CMD_DISCOVER_MODES);
+ } else if (tcpm_can_communicate_sop_prime(port) && tcpm_cable_vdm_supported(port)) {
+ tx_sop_type = TCPC_TX_SOP_PRIME;
+ svdm_version = typec_get_cable_svdm_version(typec);
+ msg[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_SVID);
+ } else {
+ tcpm_update_vdm_discovery_state(port, VDM_DISCOVERY_COMPLETE);
+ goto unlock;
+ }
+ break;
+ case VDM_DISCOVERY_CABLE_SVIDS:
+ if (modep_prime->nsvids) {
+ tx_sop_type = TCPC_TX_SOP_PRIME;
+ svdm_version = typec_get_cable_svdm_version(typec);
+ msg[0] = VDO(modep_prime->svids[0], 1, svdm_version, CMD_DISCOVER_MODES);
+ } else {
+ goto unlock;
+ }
+ break;
+ case VDM_DISCOVERY_CABLE_MODES:
+ if (modep_prime->svid_index < modep_prime->nsvids) {
+ tx_sop_type = TCPC_TX_SOP_PRIME;
+ svdm_version = typec_get_cable_svdm_version(typec);
+ msg[0] = VDO(modep_prime->svids[modep->svid_index], 1, svdm_version,
+ CMD_DISCOVER_MODES);
+ } else {
+ goto unlock;
+ }
+ break;
+ default:
goto unlock;
}
- tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0, port->tx_sop_type);
+ /* No port partner exists, and Discover Identity */
+ if (svdm_version < 0)
+ goto unlock;
+ tcpm_queue_vdm(port, msg[0], &msg[1], 0, tx_sop_type);
unlock:
mutex_unlock(&port->lock);
}
@@ -8487,12 +8620,12 @@ static enum hrtimer_restart enable_frs_timer_handler(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
-static enum hrtimer_restart send_discover_timer_handler(struct hrtimer *timer)
+static enum hrtimer_restart vdm_discovery_timer_handler(struct hrtimer *timer)
{
- struct tcpm_port *port = container_of(timer, struct tcpm_port, send_discover_timer);
+ struct tcpm_port *port = container_of(timer, struct tcpm_port, vdm_discovery_timer);
if (port->registered)
- kthread_queue_work(port->wq, &port->send_discover_work);
+ kthread_queue_work(port->wq, &port->vdm_discovery_work);
return HRTIMER_NORESTART;
}
@@ -8526,14 +8659,14 @@ struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
kthread_init_work(&port->vdm_state_machine, vdm_state_machine_work);
kthread_init_work(&port->event_work, tcpm_pd_event_handler);
kthread_init_work(&port->enable_frs, tcpm_enable_frs_work);
- kthread_init_work(&port->send_discover_work, tcpm_send_discover_work);
+ kthread_init_work(&port->vdm_discovery_work, tcpm_vdm_discovery_work);
hrtimer_setup(&port->state_machine_timer, state_machine_timer_handler, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
hrtimer_setup(&port->vdm_state_machine_timer, vdm_state_machine_timer_handler,
CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer_setup(&port->enable_frs_timer, enable_frs_timer_handler, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
- hrtimer_setup(&port->send_discover_timer, send_discover_timer_handler, CLOCK_MONOTONIC,
+ hrtimer_setup(&port->vdm_discovery_timer, vdm_discovery_timer_handler, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
spin_lock_init(&port->pd_event_lock);
@@ -8628,7 +8761,7 @@ void tcpm_unregister_port(struct tcpm_port *port)
port->registered = false;
kthread_destroy_worker(port->wq);
- hrtimer_cancel(&port->send_discover_timer);
+ hrtimer_cancel(&port->vdm_discovery_timer);
hrtimer_cancel(&port->enable_frs_timer);
hrtimer_cancel(&port->vdm_state_machine_timer);
hrtimer_cancel(&port->state_machine_timer);
base-commit: 511e746700ee6e93104d061a87743906128ab709
--
2.54.0.1189.g8c84645362-goog
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2026-06-15 19:49 [PATCH v1] usb: typec: tcpm: implement retry mechanism for Discover Identity VDMs RD Babiera
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