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Message-Id: <20210506171026.1736828-2-kyletso@google.com>
Date: Fri, 7 May 2021 01:10:25 +0800
From: Kyle Tso <kyletso@...gle.com>
To: linux@...ck-us.net, heikki.krogerus@...ux.intel.com,
gregkh@...uxfoundation.org
Cc: badhri@...gle.com, linux-usb@...r.kernel.org,
linux-kernel@...r.kernel.org, Kyle Tso <kyletso@...gle.com>
Subject: [PATCH v2 1/2] usb: typec: tcpm: Send DISCOVER_IDENTITY from
dedicated work
In current design, DISCOVER_IDENTITY is queued to VDM state machine
immediately in Ready states and never retries if it fails in the AMS.
Move the process to a delayed work so that when it fails for some
reasons (e.g. Sink Tx No Go), it can be retried by queueing the work
again. Also fix a problem that the vdm_state is not set to a proper
state if it is blocked by Collision Avoidance mechanism.
Signed-off-by: Kyle Tso <kyletso@...gle.com>
---
drivers/usb/typec/tcpm/tcpm.c | 85 ++++++++++++++++++++++++++++++-----
1 file changed, 75 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index c4fdc00a3bc8..07a449f0e8fa 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -259,6 +259,7 @@ 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
struct pd_mode_data {
int svid_index; /* current SVID index */
@@ -366,6 +367,8 @@ 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;
bool state_machine_running;
bool vdm_sm_running;
@@ -1178,6 +1181,16 @@ 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)
+{
+ if (delay_ms) {
+ hrtimer_start(&port->send_discover_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);
+ }
+}
+
static void tcpm_set_state(struct tcpm_port *port, enum tcpm_state state,
unsigned int delay_ms)
{
@@ -1855,6 +1868,9 @@ static void vdm_run_state_machine(struct tcpm_port *port)
res = tcpm_ams_start(port, DISCOVER_IDENTITY);
if (res == 0)
port->send_discover = false;
+ else if (res == -EAGAIN)
+ mod_send_discover_delayed_work(port,
+ SEND_DISCOVER_RETRY_MS);
break;
case CMD_DISCOVER_SVID:
res = tcpm_ams_start(port, DISCOVER_SVIDS);
@@ -1880,6 +1896,7 @@ static void vdm_run_state_machine(struct tcpm_port *port)
}
if (res < 0) {
+ port->vdm_state = VDM_STATE_ERR_BUSY;
port->vdm_sm_running = false;
return;
}
@@ -3682,14 +3699,6 @@ static inline enum tcpm_state unattached_state(struct tcpm_port *port)
return SNK_UNATTACHED;
}
-static void tcpm_check_send_discover(struct tcpm_port *port)
-{
- if ((port->data_role == TYPEC_HOST || port->negotiated_rev > PD_REV20) &&
- port->send_discover && port->pd_capable)
- tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0);
- port->send_discover = false;
-}
-
static void tcpm_swap_complete(struct tcpm_port *port, int result)
{
if (port->swap_pending) {
@@ -3926,7 +3935,18 @@ static void run_state_machine(struct tcpm_port *port)
break;
}
- tcpm_check_send_discover(port);
+ /*
+ * 6.4.4.3.1 Discover Identity
+ * "The Discover Identity Command Shall only be sent to SOP when there is an
+ * Explicit Contract."
+ * For now, this driver only supports SOP for DISCOVER_IDENTITY, thus using
+ * port->explicit_contract to decide whether to send the command.
+ */
+ if (port->explicit_contract)
+ mod_send_discover_delayed_work(port, 0);
+ else
+ port->send_discover = false;
+
/*
* 6.3.5
* Sending ping messages is not necessary if
@@ -4194,7 +4214,18 @@ static void run_state_machine(struct tcpm_port *port)
break;
}
- tcpm_check_send_discover(port);
+ /*
+ * 6.4.4.3.1 Discover Identity
+ * "The Discover Identity Command Shall only be sent to SOP when there is an
+ * Explicit Contract."
+ * For now, this driver only supports SOP for DISCOVER_IDENTITY, thus using
+ * port->explicit_contract.
+ */
+ if (port->explicit_contract)
+ mod_send_discover_delayed_work(port, 0);
+ else
+ port->send_discover = false;
+
power_supply_changed(port->psy);
break;
@@ -5288,6 +5319,29 @@ static void tcpm_enable_frs_work(struct kthread_work *work)
mutex_unlock(&port->lock);
}
+static void tcpm_send_discover_work(struct kthread_work *work)
+{
+ struct tcpm_port *port = container_of(work, struct tcpm_port, send_discover_work);
+
+ mutex_lock(&port->lock);
+ /* No need to send DISCOVER_IDENTITY anymore */
+ if (!port->send_discover)
+ goto unlock;
+
+ /* Retry if the port is not idle */
+ if ((port->state != SRC_READY && port->state != SNK_READY) || port->vdm_sm_running) {
+ mod_send_discover_delayed_work(port, SEND_DISCOVER_RETRY_MS);
+ goto unlock;
+ }
+
+ /* Only send the Message if the port is host for PD rev2.0 */
+ if (port->data_role == TYPEC_HOST || port->negotiated_rev > PD_REV20)
+ tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0);
+
+unlock:
+ mutex_unlock(&port->lock);
+}
+
static int tcpm_dr_set(struct typec_port *p, enum typec_data_role data)
{
struct tcpm_port *port = typec_get_drvdata(p);
@@ -6093,6 +6147,14 @@ 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)
+{
+ struct tcpm_port *port = container_of(timer, struct tcpm_port, send_discover_timer);
+
+ kthread_queue_work(port->wq, &port->send_discover_work);
+ return HRTIMER_NORESTART;
+}
+
struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
{
struct tcpm_port *port;
@@ -6123,12 +6185,15 @@ 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);
hrtimer_init(&port->state_machine_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
port->state_machine_timer.function = state_machine_timer_handler;
hrtimer_init(&port->vdm_state_machine_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
port->vdm_state_machine_timer.function = vdm_state_machine_timer_handler;
hrtimer_init(&port->enable_frs_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
port->enable_frs_timer.function = enable_frs_timer_handler;
+ hrtimer_init(&port->send_discover_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ port->send_discover_timer.function = send_discover_timer_handler;
spin_lock_init(&port->pd_event_lock);
--
2.31.1.527.g47e6f16901-goog
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