[PATCH v6 0/2] usb: typec: ucsi: allow retry to find role switch

[PATCH v6 0/2] usb: typec: ucsi: allow retry to find role switch

[Linyu Yuan]

when one role switch module built as module, it may load late than
ucsi, this change series allow retry from ucsi.

v2: improve ucsi_connector_clean() to cover all condition,
    and add one new change to avoid allocate one unused connector.

v3: fix comment from ucsi maintainer.

v4: fix review comment from Heikki Krogerus,
    merge patch#1 and patch#2 in V3 into one patch,
    add counter for retry limit,
    and some other minor fix.

v5: only update commit description of two patches

v6: fix review comment from Heikki Krogerus,
    merge patch#1 and patch#2 in v5 into one change,
    remove con->port = NULL; which is not needed.
    add Revieved-by tag for patch#3 in v5.

Linyu Yuan (2):
  usb: typec: ucsi: add a common function ucsi_unregister_connectors()
  usb: typec: ucsi: Wait for the USB role switches

 drivers/usb/typec/ucsi/ucsi.c | 85 +++++++++++++++++++++++++------------------
 drivers/usb/typec/ucsi/ucsi.h |  6 ++-
 2 files changed, 54 insertions(+), 37 deletions(-)

-- 
2.7.4

[PATCH v6 1/2] usb: typec: ucsi: add a common function ucsi_unregister_connectors()

[Linyu Yuan]

In error path of ucsi_init(), it will unregister all valid ucsi connectors,
and similar operation also happen in ucsi_unregister(),
add a common function ucsi_unregister_connectors() for two places.

Also in ucsi_init(), it allocate number of (ucsi->cap.num_connectors + 1)
connectors, there is one extra as the ending,
ucsi_unregister_connectors() is safe to unregister all ucsi connectors
according ucsi->cap.num_connectors,
remove the extra one connector to save memory.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
v2: improve ucsi_connector_clean(), check total number of connector.
v3: rename to ucsi_unregister_connectors(), suggest by maintainer
v4: merge patch#1 in V3, fix a typo samiliar -> similar in commit description
v5: no change
v6: merge patch#2 in v5 to this one,
    remove con->port = NULL; and change break condition
    in ucsi_unregister_connectors().

 drivers/usb/typec/ucsi/ucsi.c | 53 +++++++++++++++++++++++--------------------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index f0c2fa1..981b561 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1186,6 +1186,32 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
 	return ret;
 }
 
+static void ucsi_unregister_connectors(struct ucsi *ucsi)
+{
+	struct ucsi_connector *con;
+	int i;
+
+	if (!ucsi->connector)
+		return;
+
+	for (i = 0; i < ucsi->cap.num_connectors; i++) {
+		con = &ucsi->connector[i];
+		if (IS_ERR_OR_NULL(con->port))
+			break;
+
+		cancel_work_sync(&con->work);
+		ucsi_unregister_partner(con);
+		ucsi_unregister_altmodes(con, UCSI_RECIPIENT_CON);
+		ucsi_unregister_port_psy(con);
+		if (con->wq)
+			destroy_workqueue(con->wq);
+		typec_unregister_port(con->port);
+	}
+
+	kfree(ucsi->connector);
+	ucsi->connector = NULL;
+}
+
 /**
  * ucsi_init - Initialize UCSI interface
  * @ucsi: UCSI to be initialized
@@ -1194,7 +1220,6 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
  */
 static int ucsi_init(struct ucsi *ucsi)
 {
-	struct ucsi_connector *con;
 	u64 command;
 	int ret;
 	int i;
@@ -1225,7 +1250,7 @@ static int ucsi_init(struct ucsi *ucsi)
 	}
 
 	/* Allocate the connectors. Released in ucsi_unregister() */
-	ucsi->connector = kcalloc(ucsi->cap.num_connectors + 1,
+	ucsi->connector = kcalloc(ucsi->cap.num_connectors,
 				  sizeof(*ucsi->connector), GFP_KERNEL);
 	if (!ucsi->connector) {
 		ret = -ENOMEM;
@@ -1249,15 +1274,7 @@ static int ucsi_init(struct ucsi *ucsi)
 	return 0;
 
 err_unregister:
-	for (con = ucsi->connector; con->port; con++) {
-		ucsi_unregister_partner(con);
-		ucsi_unregister_altmodes(con, UCSI_RECIPIENT_CON);
-		ucsi_unregister_port_psy(con);
-		if (con->wq)
-			destroy_workqueue(con->wq);
-		typec_unregister_port(con->port);
-		con->port = NULL;
-	}
+	ucsi_unregister_connectors(ucsi);
 
 err_reset:
 	memset(&ucsi->cap, 0, sizeof(ucsi->cap));
@@ -1363,7 +1380,6 @@ EXPORT_SYMBOL_GPL(ucsi_register);
 void ucsi_unregister(struct ucsi *ucsi)
 {
 	u64 cmd = UCSI_SET_NOTIFICATION_ENABLE;
-	int i;
 
 	/* Make sure that we are not in the middle of driver initialization */
 	cancel_work_sync(&ucsi->work);
@@ -1371,18 +1387,7 @@ void ucsi_unregister(struct ucsi *ucsi)
 	/* Disable notifications */
 	ucsi->ops->async_write(ucsi, UCSI_CONTROL, &cmd, sizeof(cmd));
 
-	for (i = 0; i < ucsi->cap.num_connectors; i++) {
-		cancel_work_sync(&ucsi->connector[i].work);
-		ucsi_unregister_partner(&ucsi->connector[i]);
-		ucsi_unregister_altmodes(&ucsi->connector[i],
-					 UCSI_RECIPIENT_CON);
-		ucsi_unregister_port_psy(&ucsi->connector[i]);
-		if (ucsi->connector[i].wq)
-			destroy_workqueue(ucsi->connector[i].wq);
-		typec_unregister_port(ucsi->connector[i].port);
-	}
-
-	kfree(ucsi->connector);
+	ucsi_unregister_connectors(ucsi);
 }
 EXPORT_SYMBOL_GPL(ucsi_unregister);
 
-- 
2.7.4

[PATCH v6 2/2] usb: typec: ucsi: Wait for the USB role switches

[Linyu Yuan]

When role switch module probe late than ucsi module,
fwnode_usb_role_switch_get() will return -EPROBE_DEFER,
it is better to restart ucsi init work to find
it again every 100ms, total wait time is 10 second.

It also means change ucsi init work to delayed_work.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
v2: keep original con->num in debug log
v3: change return value from -EAGAIN to PTR_ERR()
v4: change subject line,
    add counter for retry limit,
    correct commit descripton to match change in V3
v5: small update of commit description
v6: add Reviewed-by tag of ucsi maintainer.

 drivers/usb/typec/ucsi/ucsi.c | 32 ++++++++++++++++++++------------
 drivers/usb/typec/ucsi/ucsi.h |  6 +++++-
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 981b561..20d368a 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1053,6 +1053,14 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
 	con->num = index + 1;
 	con->ucsi = ucsi;
 
+	cap->fwnode = ucsi_find_fwnode(con);
+	con->usb_role_sw = fwnode_usb_role_switch_get(cap->fwnode);
+	if (IS_ERR(con->usb_role_sw)) {
+		dev_err(ucsi->dev, "con%d: failed to get usb role switch\n",
+			con->num);
+		return PTR_ERR(con->usb_role_sw);
+	}
+
 	/* Delay other interactions with the con until registration is complete */
 	mutex_lock(&con->lock);
 
@@ -1088,7 +1096,6 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
 	if (con->cap.op_mode & UCSI_CONCAP_OPMODE_DEBUG_ACCESSORY)
 		*accessory = TYPEC_ACCESSORY_DEBUG;
 
-	cap->fwnode = ucsi_find_fwnode(con);
 	cap->driver_data = con;
 	cap->ops = &ucsi_ops;
 
@@ -1146,13 +1153,6 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
 		ucsi_port_psy_changed(con);
 	}
 
-	con->usb_role_sw = fwnode_usb_role_switch_get(cap->fwnode);
-	if (IS_ERR(con->usb_role_sw)) {
-		dev_err(ucsi->dev, "con%d: failed to get usb role switch\n",
-			con->num);
-		con->usb_role_sw = NULL;
-	}
-
 	/* Only notify USB controller if partner supports USB data */
 	if (!(UCSI_CONSTAT_PARTNER_FLAGS(con->status.flags) & UCSI_CONSTAT_PARTNER_FLAG_USB))
 		u_role = USB_ROLE_NONE;
@@ -1285,12 +1285,20 @@ static int ucsi_init(struct ucsi *ucsi)
 
 static void ucsi_init_work(struct work_struct *work)
 {
-	struct ucsi *ucsi = container_of(work, struct ucsi, work);
+	struct ucsi *ucsi = container_of(work, struct ucsi, work.work);
 	int ret;
 
 	ret = ucsi_init(ucsi);
 	if (ret)
 		dev_err(ucsi->dev, "PPM init failed (%d)\n", ret);
+
+	if (ret == -EPROBE_DEFER) {
+		if (ucsi->work_count++ > UCSI_ROLE_SWITCH_WAIT_COUNT)
+			return;
+
+		queue_delayed_work(system_long_wq, &ucsi->work,
+				   UCSI_ROLE_SWITCH_INTERVAL);
+	}
 }
 
 /**
@@ -1330,7 +1338,7 @@ struct ucsi *ucsi_create(struct device *dev, const struct ucsi_operations *ops)
 	if (!ucsi)
 		return ERR_PTR(-ENOMEM);
 
-	INIT_WORK(&ucsi->work, ucsi_init_work);
+	INIT_DELAYED_WORK(&ucsi->work, ucsi_init_work);
 	mutex_init(&ucsi->ppm_lock);
 	ucsi->dev = dev;
 	ucsi->ops = ops;
@@ -1365,7 +1373,7 @@ int ucsi_register(struct ucsi *ucsi)
 	if (!ucsi->version)
 		return -ENODEV;
 
-	queue_work(system_long_wq, &ucsi->work);
+	queue_delayed_work(system_long_wq, &ucsi->work, 0);
 
 	return 0;
 }
@@ -1382,7 +1390,7 @@ void ucsi_unregister(struct ucsi *ucsi)
 	u64 cmd = UCSI_SET_NOTIFICATION_ENABLE;
 
 	/* Make sure that we are not in the middle of driver initialization */
-	cancel_work_sync(&ucsi->work);
+	cancel_delayed_work_sync(&ucsi->work);
 
 	/* Disable notifications */
 	ucsi->ops->async_write(ucsi, UCSI_CONTROL, &cmd, sizeof(cmd));
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index 280f1e1..8eb391e 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -287,7 +287,11 @@ struct ucsi {
 	struct ucsi_capability cap;
 	struct ucsi_connector *connector;
 
-	struct work_struct work;
+	struct delayed_work work;
+	int work_count;
+#define UCSI_ROLE_SWITCH_RETRY_PER_HZ	10
+#define UCSI_ROLE_SWITCH_INTERVAL	(HZ / UCSI_ROLE_SWITCH_RETRY_PER_HZ)
+#define UCSI_ROLE_SWITCH_WAIT_COUNT	(10 * UCSI_ROLE_SWITCH_RETRY_PER_HZ)
 
 	/* PPM Communication lock */
 	struct mutex ppm_lock;
-- 
2.7.4