[PATCH 0/3] usb: typec: ucsi: allow retry to find role switch

[PATCH 0/3] usb: typec: ucsi: allow retry to find role switch

[Linyu Yuan]

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

Linyu Yuan (3):
  usb: typec: ucsi: set con->port to NULL when register port fail
  usb: typec: ucsi: add a common function ucsi_connector_clean()
  usb: typec: ucsi: retry find role swithch when module load late

 drivers/usb/typec/ucsi/ucsi.c | 75 +++++++++++++++++++++++--------------------
 drivers/usb/typec/ucsi/ucsi.h |  2 +-
 2 files changed, 41 insertions(+), 36 deletions(-)

-- 
2.7.4

[PATCH 1/3] usb: typec: ucsi: set con->port to NULL when register port fail

[Linyu Yuan]

As con->port will be used in error path of ucsi_init(),
it should be NULL or valid.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
 drivers/usb/typec/ucsi/ucsi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index f0c2fa1..77ac0b7 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1100,6 +1100,7 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
 	con->port = typec_register_port(ucsi->dev, cap);
 	if (IS_ERR(con->port)) {
 		ret = PTR_ERR(con->port);
+		con->port = NULL;
 		goto out;
 	}
 
-- 
2.7.4

[PATCH 2/3] usb: typec: ucsi: add a common function ucsi_connector_clean()

[Linyu Yuan]

In error path of ucsi_init(), it will clean all valid ucsi connector,
and samiliar operation also happen in ucsi_unregister(),
add a common function for two places.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
 drivers/usb/typec/ucsi/ucsi.c | 46 +++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 77ac0b7..684fc4f 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1187,6 +1187,27 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
 	return ret;
 }
 
+static void ucsi_connector_clean(struct ucsi *ucsi)
+{
+	struct ucsi_connector *con;
+
+	if (!ucsi->connector)
+		return;
+
+	for (con = ucsi->connector; con->port; con++) {
+		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
@@ -1195,7 +1216,6 @@ 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;
@@ -1250,15 +1270,7 @@ 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_connector_clean(ucsi);
 
 err_reset:
 	memset(&ucsi->cap, 0, sizeof(ucsi->cap));
@@ -1364,7 +1376,6 @@ 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);
@@ -1372,18 +1383,7 @@ 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_connector_clean(ucsi);
 }
 EXPORT_SYMBOL_GPL(ucsi_unregister);
 
-- 
2.7.4

Re: [PATCH 2/3] usb: typec: ucsi: add a common function ucsi_connector_clean()

[Heikki Krogerus]

On Tue, Apr 12, 2022 at 06:30:06PM +0800, Linyu Yuan wrote:
> In error path of ucsi_init(), it will clean all valid ucsi connector,
> and samiliar operation also happen in ucsi_unregister(),
> add a common function for two places.
> 
> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> ---
>  drivers/usb/typec/ucsi/ucsi.c | 46 +++++++++++++++++++++----------------------
>  1 file changed, 23 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 77ac0b7..684fc4f 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -1187,6 +1187,27 @@ static int ucsi_register_port(struct ucsi *ucsi, int index)
>  	return ret;
>  }
>  
> +static void ucsi_connector_clean(struct ucsi *ucsi)
> +{
> +	struct ucsi_connector *con;
> +
> +	if (!ucsi->connector)
> +		return;
> +
> +	for (con = ucsi->connector; con->port; con++) {
> +		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;
> +}

This looks OK, but the name of the function is confusing to me. Can
you make that ucsi_remove_connectors(), or perhaps
ucsi_unregister_connectors() to keep it alligned with the other
function names in this driver?

>  /**
>   * ucsi_init - Initialize UCSI interface
>   * @ucsi: UCSI to be initialized
> @@ -1195,7 +1216,6 @@ 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;
> @@ -1250,15 +1270,7 @@ 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_connector_clean(ucsi);
>  
>  err_reset:
>  	memset(&ucsi->cap, 0, sizeof(ucsi->cap));
> @@ -1364,7 +1376,6 @@ 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);
> @@ -1372,18 +1383,7 @@ 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_connector_clean(ucsi);
>  }
>  EXPORT_SYMBOL_GPL(ucsi_unregister);
>  
> -- 
> 2.7.4

thanks,

-- 
heikki

RE: [PATCH 2/3] usb: typec: ucsi: add a common function ucsi_connector_clean()

[Linyu Yuan (QUIC)]

> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Sent: Wednesday, April 13, 2022 3:38 PM
> To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> Subject: Re: [PATCH 2/3] usb: typec: ucsi: add a common function
> ucsi_connector_clean()
> 
> On Tue, Apr 12, 2022 at 06:30:06PM +0800, Linyu Yuan wrote:
> > In error path of ucsi_init(), it will clean all valid ucsi connector,
> > and samiliar operation also happen in ucsi_unregister(),
> > add a common function for two places.
> >
> > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> > ---
> >  drivers/usb/typec/ucsi/ucsi.c | 46 +++++++++++++++++++++----------------
> ------
> >  1 file changed, 23 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > index 77ac0b7..684fc4f 100644
> > --- a/drivers/usb/typec/ucsi/ucsi.c
> > +++ b/drivers/usb/typec/ucsi/ucsi.c
> > @@ -1187,6 +1187,27 @@ static int ucsi_register_port(struct ucsi *ucsi, int
> index)
> >  	return ret;
> >  }
> >
> > +static void ucsi_connector_clean(struct ucsi *ucsi)
> > +{
> > +	struct ucsi_connector *con;
> > +
> > +	if (!ucsi->connector)
> > +		return;
> > +
> > +	for (con = ucsi->connector; con->port; con++) {
> > +		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;
> > +}
> 
> This looks OK, but the name of the function is confusing to me. Can
> you make that ucsi_remove_connectors(), or perhaps
> ucsi_unregister_connectors() to keep it alligned with the other
> function names in this driver?
Thanks, will choose ucsi_unregister_connectors().
> 
> >  /**
> >   * ucsi_init - Initialize UCSI interface
> >   * @ucsi: UCSI to be initialized
> > @@ -1195,7 +1216,6 @@ 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;
> > @@ -1250,15 +1270,7 @@ 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_connector_clean(ucsi);
> >
> >  err_reset:
> >  	memset(&ucsi->cap, 0, sizeof(ucsi->cap));
> > @@ -1364,7 +1376,6 @@ 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);
> > @@ -1372,18 +1383,7 @@ 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_connector_clean(ucsi);
> >  }
> >  EXPORT_SYMBOL_GPL(ucsi_unregister);
> >
> > --
> > 2.7.4
> 
> thanks,
> 
> --
> heikki

[PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Linyu Yuan]

When role switch enabled, return -EAGAIN if fail to find it due to
module load ordering issue, then restart ucsi init work to find
it again every 100ms.

It also means change ucsi init work to delayed_work.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
 drivers/usb/typec/ucsi/ucsi.c | 28 ++++++++++++++++------------
 drivers/usb/typec/ucsi/ucsi.h |  2 +-
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 684fc4f..fabd4df 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",
+			index + 1);
+		return -EAGAIN;
+	}
+
 	/* 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;
 
@@ -1147,13 +1154,6 @@ 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;
@@ -1281,12 +1281,16 @@ 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 == -EAGAIN)
+		queue_delayed_work(system_long_wq, &ucsi->work, HZ/10);
 }
 
 /**
@@ -1326,7 +1330,7 @@ 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;
@@ -1361,7 +1365,7 @@ 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;
 }
@@ -1378,7 +1382,7 @@ 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..3812017 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -287,7 +287,7 @@ struct ucsi {
 	struct ucsi_capability cap;
 	struct ucsi_connector *connector;
 
-	struct work_struct work;
+	struct delayed_work work;
 
 	/* PPM Communication lock */
 	struct mutex ppm_lock;
-- 
2.7.4

Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Heikki Krogerus]

On Tue, Apr 12, 2022 at 06:30:07PM +0800, Linyu Yuan wrote:
> When role switch enabled, return -EAGAIN if fail to find it due to
> module load ordering issue, then restart ucsi init work to find
> it again every 100ms.
> 
> It also means change ucsi init work to delayed_work.
> 
> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> ---
>  drivers/usb/typec/ucsi/ucsi.c | 28 ++++++++++++++++------------
>  drivers/usb/typec/ucsi/ucsi.h |  2 +-
>  2 files changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 684fc4f..fabd4df 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",
> +			index + 1);
> +		return -EAGAIN;
> +	}

No, this is wrong. If there is a role switch assigned in the firmware
for the port, then fwnode_usb_role_switch_get() will return
-EPROBE_DEFER until the switch has been registered.

So I think what you want to do is just make the failure to get the
role switch fatal in this driver. Just return PTR_ERR(con->usb_role_sw).

thanks,

-- 
heikki

RE: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Linyu Yuan (QUIC)]

> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Sent: Wednesday, April 13, 2022 3:46 PM
> To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> Subject: Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when
> module load late
> 
> On Tue, Apr 12, 2022 at 06:30:07PM +0800, Linyu Yuan wrote:
> > When role switch enabled, return -EAGAIN if fail to find it due to
> > module load ordering issue, then restart ucsi init work to find
> > it again every 100ms.
> >
> > It also means change ucsi init work to delayed_work.
> >
> > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> > ---
> >  drivers/usb/typec/ucsi/ucsi.c | 28 ++++++++++++++++------------
> >  drivers/usb/typec/ucsi/ucsi.h |  2 +-
> >  2 files changed, 17 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > index 684fc4f..fabd4df 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",
> > +			index + 1);
> > +		return -EAGAIN;
> > +	}
> 
> No, this is wrong. If there is a role switch assigned in the firmware
> for the port, then fwnode_usb_role_switch_get() will return
> -EPROBE_DEFER until the switch has been registered.
> 
> So I think what you want to do is just make the failure to get the
> role switch fatal in this driver. Just return PTR_ERR(con->usb_role_sw).
Thanks, will change it to check -EPROBE_DEFER.
> 
> thanks,
> 
> --
> heikki

Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Heikki Krogerus]

On Wed, Apr 13, 2022 at 08:00:35AM +0000, Linyu Yuan (QUIC) wrote:
> > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > Sent: Wednesday, April 13, 2022 3:46 PM
> > To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> > usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> > Subject: Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when
> > module load late
> > 
> > On Tue, Apr 12, 2022 at 06:30:07PM +0800, Linyu Yuan wrote:
> > > When role switch enabled, return -EAGAIN if fail to find it due to
> > > module load ordering issue, then restart ucsi init work to find
> > > it again every 100ms.
> > >
> > > It also means change ucsi init work to delayed_work.
> > >
> > > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> > > ---
> > >  drivers/usb/typec/ucsi/ucsi.c | 28 ++++++++++++++++------------
> > >  drivers/usb/typec/ucsi/ucsi.h |  2 +-
> > >  2 files changed, 17 insertions(+), 13 deletions(-)
> > >
> > > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > > index 684fc4f..fabd4df 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",
> > > +			index + 1);
> > > +		return -EAGAIN;
> > > +	}
> > 
> > No, this is wrong. If there is a role switch assigned in the firmware
> > for the port, then fwnode_usb_role_switch_get() will return
> > -EPROBE_DEFER until the switch has been registered.
> > 
> > So I think what you want to do is just make the failure to get the
> > role switch fatal in this driver. Just return PTR_ERR(con->usb_role_sw).
> Thanks, will change it to check -EPROBE_DEFER.

No, you don't check that, you just return that.

So you don't need that crazy polling mechanism where you queue a work
until you get the resource. Just let the driver core handle the
situation.

thanks,

-- 
heikki

RE: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Linyu Yuan (QUIC)]

> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Sent: Wednesday, April 13, 2022 4:10 PM
> To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> Subject: Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when
> module load late
> 
> On Wed, Apr 13, 2022 at 08:00:35AM +0000, Linyu Yuan (QUIC) wrote:
> > > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > Sent: Wednesday, April 13, 2022 3:46 PM
> > > To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> > > usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> > > Subject: Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when
> > > module load late
> > >
> > > On Tue, Apr 12, 2022 at 06:30:07PM +0800, Linyu Yuan wrote:
> > > > When role switch enabled, return -EAGAIN if fail to find it due to
> > > > module load ordering issue, then restart ucsi init work to find
> > > > it again every 100ms.
> > > >
> > > > It also means change ucsi init work to delayed_work.
> > > >
> > > > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> > > > ---
> > > >  drivers/usb/typec/ucsi/ucsi.c | 28 ++++++++++++++++------------
> > > >  drivers/usb/typec/ucsi/ucsi.h |  2 +-
> > > >  2 files changed, 17 insertions(+), 13 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/typec/ucsi/ucsi.c
> b/drivers/usb/typec/ucsi/ucsi.c
> > > > index 684fc4f..fabd4df 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",
> > > > +			index + 1);
> > > > +		return -EAGAIN;
> > > > +	}
> > >
> > > No, this is wrong. If there is a role switch assigned in the firmware
> > > for the port, then fwnode_usb_role_switch_get() will return
> > > -EPROBE_DEFER until the switch has been registered.
> > >
> > > So I think what you want to do is just make the failure to get the
> > > role switch fatal in this driver. Just return PTR_ERR(con->usb_role_sw).
> > Thanks, will change it to check -EPROBE_DEFER.
> 
> No, you don't check that, you just return that.
Yes, I do like it.
> 
> So you don't need that crazy polling mechanism where you queue a work
> until you get the resource. Just let the driver core handle the
> situation.
The issue is when a UCSI implementation driver probe, it call ucsi_register(),
But this function will not return -EPROBE_DEFER,
It just queue a work to start connector discovery.
> 
> thanks,
> 
> --
> heikki

Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Heikki Krogerus]

On Wed, Apr 13, 2022 at 08:16:53AM +0000, Linyu Yuan (QUIC) wrote:
> > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > Sent: Wednesday, April 13, 2022 4:10 PM
> > To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> > usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> > Subject: Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when
> > module load late
> > 
> > On Wed, Apr 13, 2022 at 08:00:35AM +0000, Linyu Yuan (QUIC) wrote:
> > > > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > > Sent: Wednesday, April 13, 2022 3:46 PM
> > > > To: Linyu Yuan (QUIC) <quic_linyyuan@quicinc.com>
> > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-
> > > > usb@vger.kernel.org; Jack Pham (QUIC) <quic_jackp@quicinc.com>
> > > > Subject: Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when
> > > > module load late
> > > >
> > > > On Tue, Apr 12, 2022 at 06:30:07PM +0800, Linyu Yuan wrote:
> > > > > When role switch enabled, return -EAGAIN if fail to find it due to
> > > > > module load ordering issue, then restart ucsi init work to find
> > > > > it again every 100ms.
> > > > >
> > > > > It also means change ucsi init work to delayed_work.
> > > > >
> > > > > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> > > > > ---
> > > > >  drivers/usb/typec/ucsi/ucsi.c | 28 ++++++++++++++++------------
> > > > >  drivers/usb/typec/ucsi/ucsi.h |  2 +-
> > > > >  2 files changed, 17 insertions(+), 13 deletions(-)
> > > > >
> > > > > diff --git a/drivers/usb/typec/ucsi/ucsi.c
> > b/drivers/usb/typec/ucsi/ucsi.c
> > > > > index 684fc4f..fabd4df 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",
> > > > > +			index + 1);
> > > > > +		return -EAGAIN;
> > > > > +	}
> > > >
> > > > No, this is wrong. If there is a role switch assigned in the firmware
> > > > for the port, then fwnode_usb_role_switch_get() will return
> > > > -EPROBE_DEFER until the switch has been registered.
> > > >
> > > > So I think what you want to do is just make the failure to get the
> > > > role switch fatal in this driver. Just return PTR_ERR(con->usb_role_sw).
> > > Thanks, will change it to check -EPROBE_DEFER.
> > 
> > No, you don't check that, you just return that.
> Yes, I do like it.
> > 
> > So you don't need that crazy polling mechanism where you queue a work
> > until you get the resource. Just let the driver core handle the
> > situation.
> The issue is when a UCSI implementation driver probe, it call ucsi_register(),
> But this function will not return -EPROBE_DEFER,
> It just queue a work to start connector discovery.

Ah, right right. This is a library. But we should be able use
wait_for_device_probe().

So if fwnode_usb_role_switch_get() returns -EPROBE_DEFER, you call
wait_for_device_probe() and try again.

Br,

-- 
heikki

RE: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Linyu Yuan (QUIC)]

> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Sent: Wednesday, April 13, 2022 6:24 PM
> > > No, you don't check that, you just return that.
> > Yes, I do like it.
> > >
> > > So you don't need that crazy polling mechanism where you queue a work
> > > until you get the resource. Just let the driver core handle the
> > > situation.
> > The issue is when a UCSI implementation driver probe, it call ucsi_register(),
> > But this function will not return -EPROBE_DEFER,
> > It just queue a work to start connector discovery.
> 
> Ah, right right. This is a library. But we should be able use
> wait_for_device_probe().
> 
> So if fwnode_usb_role_switch_get() returns -EPROBE_DEFER, you call
> wait_for_device_probe() and try again.
Do you mean do as below,

find_role_switch:
	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);
		if (con->usb_role_sw == -EPROBE_DEFER) {
			wait_for_device_probe();
			goto find_role_switch;
		}

		return PTR_ERR(con->usb_role_sw);
	}

Seem wait_for_device_probe() will wait all drivers probe,
Can we accept it ?
> 
> Br,
> 
> --
> heikki

Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Heikki Krogerus]

On Wed, Apr 13, 2022 at 11:01:23AM +0000, Linyu Yuan (QUIC) wrote:
> > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > Sent: Wednesday, April 13, 2022 6:24 PM
> > > > No, you don't check that, you just return that.
> > > Yes, I do like it.
> > > >
> > > > So you don't need that crazy polling mechanism where you queue a work
> > > > until you get the resource. Just let the driver core handle the
> > > > situation.
> > > The issue is when a UCSI implementation driver probe, it call ucsi_register(),
> > > But this function will not return -EPROBE_DEFER,
> > > It just queue a work to start connector discovery.
> > 
> > Ah, right right. This is a library. But we should be able use
> > wait_for_device_probe().
> > 
> > So if fwnode_usb_role_switch_get() returns -EPROBE_DEFER, you call
> > wait_for_device_probe() and try again.
> Do you mean do as below,
> 
> find_role_switch:
> 	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);
> 		if (con->usb_role_sw == -EPROBE_DEFER) {
> 			wait_for_device_probe();
> 			goto find_role_switch;
> 		}
> 
> 		return PTR_ERR(con->usb_role_sw);
> 	}

Yes, something like that. Perhaps you could just do that in a loop,
and you should have a delay there.

> Seem wait_for_device_probe() will wait all drivers probe,
> Can we accept it ?

That part is not a problem, but I'm not sure if it appropriate to call
the function from drivers. Let me check if there is something else
that we can do...

thanks,

-- 
heikki

Re: [PATCH 3/3] usb: typec: ucsi: retry find role swithch when module load late

[Heikki Krogerus]

On Wed, Apr 13, 2022 at 02:19:49PM +0300, Heikki Krogerus wrote:
> On Wed, Apr 13, 2022 at 11:01:23AM +0000, Linyu Yuan (QUIC) wrote:
> > > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > Sent: Wednesday, April 13, 2022 6:24 PM
> > > > > No, you don't check that, you just return that.
> > > > Yes, I do like it.
> > > > >
> > > > > So you don't need that crazy polling mechanism where you queue a work
> > > > > until you get the resource. Just let the driver core handle the
> > > > > situation.
> > > > The issue is when a UCSI implementation driver probe, it call ucsi_register(),
> > > > But this function will not return -EPROBE_DEFER,
> > > > It just queue a work to start connector discovery.
> > > 
> > > Ah, right right. This is a library. But we should be able use
> > > wait_for_device_probe().
> > > 
> > > So if fwnode_usb_role_switch_get() returns -EPROBE_DEFER, you call
> > > wait_for_device_probe() and try again.
> > Do you mean do as below,
> > 
> > find_role_switch:
> > 	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);
> > 		if (con->usb_role_sw == -EPROBE_DEFER) {
> > 			wait_for_device_probe();
> > 			goto find_role_switch;
> > 		}
> > 
> > 		return PTR_ERR(con->usb_role_sw);
> > 	}
> 
> Yes, something like that. Perhaps you could just do that in a loop,
> and you should have a delay there.
> 
> > Seem wait_for_device_probe() will wait all drivers probe,
> > Can we accept it ?
> 
> That part is not a problem, but I'm not sure if it appropriate to call
> the function from drivers. Let me check if there is something else
> that we can do...

OK, I don't think we should use that in drivers, and I don't have any
better ideas. Sorry for the noise.

I notised that you have already send a couple of new versions of this
series. I'll review the last one of those, but in the future please
don't send the new versions so fast.

thanks,

-- 
heikki