fix HCD PHY suspend handling

Before this patch usb_phy_roothub_init served two purposes (from a caller's point of view - like hcd.c):
- parsing the PHYs and allocating the list entries
- calling phy_init on each list entry

While this worked so far it has one disadvantage: if we need to call phy_init for each PHY instance then the existing code cannot be re-used. Solve this by splitting off usb_phy_roothub_alloc which only parses the PHYs and allocates the list entries.
usb_phy_roothub_init then gets a struct usb_phy_roothub and only calls phy_init on each PHY instance (along with the corresponding cleanup if that failed somewhere).

This is a preparation step for adding proper suspend support for some hardware that requires phy_exit to be called during suspend and phy_init to be called during resume.

Signed-off-by Martin Blumenstingl <[email protected]>

---
 drivers/usb/core/hcd.c | 10 +++++++---
 drivers/usb/core/phy.c | 53 +++++++++++++++++++++++++-------------------------
 drivers/usb/core/phy.h |  4 +++-
 3 files changed, 37 insertions(+), 30 deletions(-)

drivers/usb/core/hcd.c +7 -3

index 777036ae6367..15b0418e3b6a 100644
@@ -2758,12 +2758,16 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	}
 
 	if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
-		hcd->phy_roothub = usb_phy_roothub_init(hcd->self.sysdev);
+		hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
 		if (IS_ERR(hcd->phy_roothub)) {
 			retval = PTR_ERR(hcd->phy_roothub);
-			goto err_phy_roothub_init;
+			goto err_phy_roothub_alloc;
 		}
 
+		retval = usb_phy_roothub_init(hcd->phy_roothub);
+		if (retval)
+			goto err_phy_roothub_alloc;
+
 		retval = usb_phy_roothub_power_on(hcd->phy_roothub);
 		if (retval)
 			goto err_usb_phy_roothub_power_on;

@@ -2936,7 +2940,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	usb_phy_roothub_power_off(hcd->phy_roothub);
 err_usb_phy_roothub_power_on:
 	usb_phy_roothub_exit(hcd->phy_roothub);
-err_phy_roothub_init:
+err_phy_roothub_alloc:
 	if (hcd->remove_phy && hcd->usb_phy) {
 		usb_phy_shutdown(hcd->usb_phy);
 		usb_put_phy(hcd->usb_phy);

drivers/usb/core/phy.c +27 -26

index f19aaa3c899c..44f008cda7a8 100644
@@ -19,19 +19,6 @@ struct usb_phy_roothub {
 	struct list_head	list;
 };
 
-static struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
-{
-	struct usb_phy_roothub *roothub_entry;
-
-	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
-	if (!roothub_entry)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&roothub_entry->list);
-
-	return roothub_entry;
-}
-
 static int usb_phy_roothub_add_phy(struct device *dev, int index,
 				   struct list_head *list)
 {

@@ -45,9 +32,11 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
 			return PTR_ERR(phy);
 	}
 
-	roothub_entry = usb_phy_roothub_alloc(dev);
-	if (IS_ERR(roothub_entry))
-		return PTR_ERR(roothub_entry);
+	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
+	if (!roothub_entry)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&roothub_entry->list);
 
 	roothub_entry->phy = phy;
 

@@ -56,11 +45,9 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
 	return 0;
 }
 
-struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
+struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
 {
 	struct usb_phy_roothub *phy_roothub;
-	struct usb_phy_roothub *roothub_entry;
-	struct list_head *head;
 	int i, num_phys, err;
 
 	num_phys = of_count_phandle_with_args(dev->of_node, "phys",

@@ -68,16 +55,31 @@ struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
 	if (num_phys <= 0)
 		return NULL;
 
-	phy_roothub = usb_phy_roothub_alloc(dev);
-	if (IS_ERR(phy_roothub))
-		return phy_roothub;
+	phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
+	if (!phy_roothub)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&phy_roothub->list);
 
 	for (i = 0; i < num_phys; i++) {
 		err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
 		if (err)
-			goto err_out;
+			return ERR_PTR(err);
 	}
 
+	return phy_roothub;
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc);
+
+int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub)
+{
+	struct usb_phy_roothub *roothub_entry;
+	struct list_head *head;
+	int err;
+
+	if (!phy_roothub)
+		return 0;
+
 	head = &phy_roothub->list;
 
 	list_for_each_entry(roothub_entry, head, list) {

@@ -86,14 +88,13 @@ struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
 			goto err_exit_phys;
 	}
 
-	return phy_roothub;
+	return 0;
 
 err_exit_phys:
 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
 		phy_exit(roothub_entry->phy);
 
-err_out:
-	return ERR_PTR(err);
+	return err;
 }
 EXPORT_SYMBOL_GPL(usb_phy_roothub_init);
 

drivers/usb/core/phy.h +0 -0

index 6fde59bfbff8..eb31253201ad 100644

Before this patch usb_phy_roothub_init served two purposes (from a caller's point of view - like hcd.c):
- parsing the PHYs and allocating the list entries
- calling phy_init on each list entry

While this worked so far it has one disadvantage: if we need to call phy_init for each PHY instance then the existing code cannot be re-used. Solve this by splitting off usb_phy_roothub_alloc which only parses the PHYs and allocates the list entries.
usb_phy_roothub_init then gets a struct usb_phy_roothub and only calls phy_init on each PHY instance (along with the corresponding cleanup if that failed somewhere).

This is a preparation step for adding proper suspend support for some hardware that requires phy_exit to be called during suspend and phy_init to be called during resume.

Signed-off-by Martin Blumenstingl <[email protected]>

---
 drivers/usb/core/hcd.c | 10 +++++++---
 drivers/usb/core/phy.c | 53 +++++++++++++++++++++++++-------------------------
 drivers/usb/core/phy.h |  4 +++-
 3 files changed, 37 insertions(+), 30 deletions(-)

drivers/usb/core/hcd.c +7 -3

index 777036ae6367..15b0418e3b6a 100644
@@ -2758,12 +2758,16 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	}
 
 	if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
-		hcd->phy_roothub = usb_phy_roothub_init(hcd->self.sysdev);
+		hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
 		if (IS_ERR(hcd->phy_roothub)) {
 			retval = PTR_ERR(hcd->phy_roothub);
-			goto err_phy_roothub_init;
+			goto err_phy_roothub_alloc;
 		}
 
+		retval = usb_phy_roothub_init(hcd->phy_roothub);
+		if (retval)
+			goto err_phy_roothub_alloc;
+
 		retval = usb_phy_roothub_power_on(hcd->phy_roothub);
 		if (retval)
 			goto err_usb_phy_roothub_power_on;

@@ -2936,7 +2940,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	usb_phy_roothub_power_off(hcd->phy_roothub);
 err_usb_phy_roothub_power_on:
 	usb_phy_roothub_exit(hcd->phy_roothub);
-err_phy_roothub_init:
+err_phy_roothub_alloc:
 	if (hcd->remove_phy && hcd->usb_phy) {
 		usb_phy_shutdown(hcd->usb_phy);
 		usb_put_phy(hcd->usb_phy);

drivers/usb/core/phy.c +27 -26

index f19aaa3c899c..44f008cda7a8 100644
@@ -19,19 +19,6 @@ struct usb_phy_roothub {
 	struct list_head	list;
 };
 
-static struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
-{
-	struct usb_phy_roothub *roothub_entry;
-
-	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
-	if (!roothub_entry)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&roothub_entry->list);
-
-	return roothub_entry;
-}
-
 static int usb_phy_roothub_add_phy(struct device *dev, int index,
 				   struct list_head *list)
 {

@@ -45,9 +32,11 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
 			return PTR_ERR(phy);
 	}
 
-	roothub_entry = usb_phy_roothub_alloc(dev);
-	if (IS_ERR(roothub_entry))
-		return PTR_ERR(roothub_entry);
+	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
+	if (!roothub_entry)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&roothub_entry->list);
 
 	roothub_entry->phy = phy;
 

@@ -56,11 +45,9 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
 	return 0;
 }
 
-struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
+struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
 {
 	struct usb_phy_roothub *phy_roothub;
-	struct usb_phy_roothub *roothub_entry;
-	struct list_head *head;
 	int i, num_phys, err;
 
 	num_phys = of_count_phandle_with_args(dev->of_node, "phys",

@@ -68,16 +55,31 @@ struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
 	if (num_phys <= 0)
 		return NULL;
 
-	phy_roothub = usb_phy_roothub_alloc(dev);
-	if (IS_ERR(phy_roothub))
-		return phy_roothub;
+	phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
+	if (!phy_roothub)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&phy_roothub->list);
 
 	for (i = 0; i < num_phys; i++) {
 		err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
 		if (err)
-			goto err_out;
+			return ERR_PTR(err);
 	}
 
+	return phy_roothub;
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc);
+
+int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub)
+{
+	struct usb_phy_roothub *roothub_entry;
+	struct list_head *head;
+	int err;
+
+	if (!phy_roothub)
+		return 0;
+
 	head = &phy_roothub->list;
 
 	list_for_each_entry(roothub_entry, head, list) {

@@ -86,14 +88,13 @@ struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
 			goto err_exit_phys;
 	}
 
-	return phy_roothub;
+	return 0;
 
 err_exit_phys:
 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
 		phy_exit(roothub_entry->phy);
 
-err_out:
-	return ERR_PTR(err);
+	return err;
 }
 EXPORT_SYMBOL_GPL(usb_phy_roothub_init);
 

drivers/usb/core/phy.h +3 -1

index 6fde59bfbff8..eb31253201ad 100644
@@ -1,6 +1,8 @@
 struct usb_phy_roothub;
 
-struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev);
+struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev);
+
+int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub);
 int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);
 
 int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);

Quoted 13 lines · Martin Blumenstingl

Before this patch usb_phy_roothub_init served two purposes (from a caller's point of view - like hcd.c):
- parsing the PHYs and allocating the list entries
- calling phy_init on each list entry

While this worked so far it has one disadvantage: if we need to call phy_init for each PHY instance then the existing code cannot be re-used. Solve this by splitting off usb_phy_roothub_alloc which only parses the PHYs and allocates the list entries.
usb_phy_roothub_init then gets a struct usb_phy_roothub and only calls phy_init on each PHY instance (along with the corresponding cleanup if that failed somewhere).

Quoted 5 lines

This is a preparation step for adding proper suspend support for some hardware that requires phy_exit to be called during suspend and phy_init to be called during resume.

Signed-off-by Martin Blumenstingl <[email protected]>

I don't think we need RFC in subject.

If the USB controller can wake up the system (which is the case for example with the Mediatek USB3 IP) then we must not call phy_exit during suspend to ensure that the USB controller doesn't have to re-enumerate the devices during resume.
However, if the USB controller cannot wake up the system (which is the case for example on various TI platforms using a dwc3 controller) then we must call phy_exit during suspend. Otherwise the PHY driver keeps the clocks enabled, which prevents the system from reaching the lowest power levels in the suspend state.

Solve this by introducing two new functions in the PHY wrapper which are dedicated to the suspend and resume handling.
If the controller can wake up the system the new usb_phy_roothub_suspend function will simply call usb_phy_roothub_power_off. However, if wake up is not supported by the controller it will also call usb_phy_roothub_exit.
The also new usb_phy_roothub_resume function takes care of calling usb_phy_roothub_init (if the controller can't wake up the system) in addition to usb_phy_roothub_power_on.

Fixes 07dbff0ddbd86c ("usb: core: add a wrapper for the USB PHYs on the HCD")

Fixes 178a0bce05cbc1 ("usb: core: hcd: integrate the PHY wrapper into the HCD core")

Reported-by Roger Quadros <[email protected]>

Suggested-by Roger Quadros <[email protected]>

Suggested-by Chunfeng Yun <[email protected]>

Signed-off-by Martin Blumenstingl <[email protected]>

---
 drivers/usb/core/hcd.c |  8 +++++---
 drivers/usb/core/phy.c | 35 +++++++++++++++++++++++++++++++++++
 drivers/usb/core/phy.h |  5 +++++
 3 files changed, 45 insertions(+), 3 deletions(-)

drivers/usb/core/hcd.c +5 -3

index 15b0418e3b6a..78bae4ecd68b 100644
@@ -2262,7 +2262,8 @@ int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
 		hcd->state = HC_STATE_SUSPENDED;
 
 		if (!PMSG_IS_AUTO(msg))
-			usb_phy_roothub_power_off(hcd->phy_roothub);
+			usb_phy_roothub_suspend(hcd->self.sysdev,
+						hcd->phy_roothub);
 
 		/* Did we race with a root-hub wakeup event? */
 		if (rhdev->do_remote_wakeup) {

@@ -2302,7 +2303,8 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 	}
 
 	if (!PMSG_IS_AUTO(msg)) {
-		status = usb_phy_roothub_power_on(hcd->phy_roothub);
+		status = usb_phy_roothub_resume(hcd->self.sysdev,
+						hcd->phy_roothub);
 		if (status)
 			return status;
 	}

@@ -2344,7 +2346,7 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 		}
 	} else {
 		hcd->state = old_state;
-		usb_phy_roothub_power_off(hcd->phy_roothub);
+		usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
 				"resume", status);
 		if (status != -ESHUTDOWN)

drivers/usb/core/phy.c +35 -0

index 44f008cda7a8..a39d9bb26a4f 100644
@@ -157,3 +157,38 @@ void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub)
 		phy_power_off(roothub_entry->phy);
 }
 EXPORT_SYMBOL_GPL(usb_phy_roothub_power_off);
+
+int usb_phy_roothub_suspend(struct device *controller_dev,
+			    struct usb_phy_roothub *phy_roothub)
+{
+	usb_phy_roothub_power_off(phy_roothub);
+
+	/* keep the PHYs initialized so the device can wake up the system */
+	if (device_may_wakeup(controller_dev))
+		return 0;
+
+	return usb_phy_roothub_exit(phy_roothub);
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_suspend);
+
+int usb_phy_roothub_resume(struct device *controller_dev,
+			   struct usb_phy_roothub *phy_roothub)
+{
+	int err;
+
+	/* if the device can't wake up the system _exit was called */
+	if (!device_may_wakeup(controller_dev)) {
+		err = usb_phy_roothub_init(phy_roothub);
+		if (err)
+			return err;
+	}
+
+	err = usb_phy_roothub_power_on(phy_roothub);
+
+	/* undo _init if _power_on failed */
+	if (err && !device_may_wakeup(controller_dev))
+		usb_phy_roothub_exit(phy_roothub);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_resume);

drivers/usb/core/phy.h +0 -0

index eb31253201ad..605555901d44 100644

If the USB controller can wake up the system (which is the case for example with the Mediatek USB3 IP) then we must not call phy_exit during suspend to ensure that the USB controller doesn't have to re-enumerate the devices during resume.
However, if the USB controller cannot wake up the system (which is the case for example on various TI platforms using a dwc3 controller) then we must call phy_exit during suspend. Otherwise the PHY driver keeps the clocks enabled, which prevents the system from reaching the lowest power levels in the suspend state.

Solve this by introducing two new functions in the PHY wrapper which are dedicated to the suspend and resume handling.
If the controller can wake up the system the new usb_phy_roothub_suspend function will simply call usb_phy_roothub_power_off. However, if wake up is not supported by the controller it will also call usb_phy_roothub_exit.
The also new usb_phy_roothub_resume function takes care of calling usb_phy_roothub_init (if the controller can't wake up the system) in addition to usb_phy_roothub_power_on.

Fixes 07dbff0ddbd86c ("usb: core: add a wrapper for the USB PHYs on the HCD")

Fixes 178a0bce05cbc1 ("usb: core: hcd: integrate the PHY wrapper into the HCD core")

Reported-by Roger Quadros <[email protected]>

Suggested-by Roger Quadros <[email protected]>

Suggested-by Chunfeng Yun <[email protected]>

Signed-off-by Martin Blumenstingl <[email protected]>

---
 drivers/usb/core/hcd.c |  8 +++++---
 drivers/usb/core/phy.c | 35 +++++++++++++++++++++++++++++++++++
 drivers/usb/core/phy.h |  5 +++++
 3 files changed, 45 insertions(+), 3 deletions(-)

drivers/usb/core/hcd.c +5 -3

index 15b0418e3b6a..78bae4ecd68b 100644
@@ -2262,7 +2262,8 @@ int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
 		hcd->state = HC_STATE_SUSPENDED;
 
 		if (!PMSG_IS_AUTO(msg))
-			usb_phy_roothub_power_off(hcd->phy_roothub);
+			usb_phy_roothub_suspend(hcd->self.sysdev,
+						hcd->phy_roothub);
 
 		/* Did we race with a root-hub wakeup event? */
 		if (rhdev->do_remote_wakeup) {

@@ -2302,7 +2303,8 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 	}
 
 	if (!PMSG_IS_AUTO(msg)) {
-		status = usb_phy_roothub_power_on(hcd->phy_roothub);
+		status = usb_phy_roothub_resume(hcd->self.sysdev,
+						hcd->phy_roothub);
 		if (status)
 			return status;
 	}

@@ -2344,7 +2346,7 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 		}
 	} else {
 		hcd->state = old_state;
-		usb_phy_roothub_power_off(hcd->phy_roothub);
+		usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
 				"resume", status);
 		if (status != -ESHUTDOWN)

drivers/usb/core/phy.c +35 -0

index 44f008cda7a8..a39d9bb26a4f 100644
@@ -157,3 +157,38 @@ void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub)
 		phy_power_off(roothub_entry->phy);
 }
 EXPORT_SYMBOL_GPL(usb_phy_roothub_power_off);
+
+int usb_phy_roothub_suspend(struct device *controller_dev,
+			    struct usb_phy_roothub *phy_roothub)
+{
+	usb_phy_roothub_power_off(phy_roothub);
+
+	/* keep the PHYs initialized so the device can wake up the system */
+	if (device_may_wakeup(controller_dev))
+		return 0;
+
+	return usb_phy_roothub_exit(phy_roothub);
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_suspend);
+
+int usb_phy_roothub_resume(struct device *controller_dev,
+			   struct usb_phy_roothub *phy_roothub)
+{
+	int err;
+
+	/* if the device can't wake up the system _exit was called */
+	if (!device_may_wakeup(controller_dev)) {
+		err = usb_phy_roothub_init(phy_roothub);
+		if (err)
+			return err;
+	}
+
+	err = usb_phy_roothub_power_on(phy_roothub);
+
+	/* undo _init if _power_on failed */
+	if (err && !device_may_wakeup(controller_dev))
+		usb_phy_roothub_exit(phy_roothub);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_resume);

drivers/usb/core/phy.h +5 -0

index eb31253201ad..605555901d44 100644
@@ -7,3 +7,8 @@ int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);
 
 int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);
 void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub);
+
+int usb_phy_roothub_suspend(struct device *controller_dev,
+			    struct usb_phy_roothub *phy_roothub);
+int usb_phy_roothub_resume(struct device *controller_dev,
+			   struct usb_phy_roothub *phy_roothub);