[PATCH v3] usb: common: usb-conn-gpio: use a unique name for usb connector device

[PATCH v3] usb: common: usb-conn-gpio: use a unique name for usb connector device

[Chance Yang]

The current implementation of the usb-conn-gpio driver uses a fixed
"usb-charger" name for all USB connector devices. This causes conflicts
in the power supply subsystem when multiple USB connectors are present,
as duplicate names are not allowed.

Use IDA to manage unique IDs for naming usb connectors (e.g.,
usb-charger-0, usb-charger-1).

Fixes: 880287910b189 ("usb: common: usb-conn-gpio: fix NULL pointer dereference of charger")
Cc: stable@vger.kernel.org
Signed-off-by: Chance Yang <chance.yang@kneron.us>
---
Changes in v3:
- Added Cc stable
- Link to v2: https://lore.kernel.org/r/20250411-work-next-v2-1-40beb82df5a9@kneron.us

Changes in v2:
- Replaced atomic_t with IDA for unique ID management
- Link to v1: https://lore.kernel.org/r/20250411-work-next-v1-1-93c4b95ee6c1@kneron.us
---
 drivers/usb/common/usb-conn-gpio.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/common/usb-conn-gpio.c b/drivers/usb/common/usb-conn-gpio.c
index 1e36be2a28fd5ca5e1495b7923e4d3e25d7cedef..421c3af38e06975259f4a1792aa3b3708a192d59 100644
--- a/drivers/usb/common/usb-conn-gpio.c
+++ b/drivers/usb/common/usb-conn-gpio.c
@@ -21,6 +21,9 @@
 #include <linux/regulator/consumer.h>
 #include <linux/string_choices.h>
 #include <linux/usb/role.h>
+#include <linux/idr.h>
+
+static DEFINE_IDA(usb_conn_ida);
 
 #define USB_GPIO_DEB_MS		20	/* ms */
 #define USB_GPIO_DEB_US		((USB_GPIO_DEB_MS) * 1000)	/* us */
@@ -30,6 +33,7 @@
 
 struct usb_conn_info {
 	struct device *dev;
+	int conn_id; /* store the IDA-allocated ID */
 	struct usb_role_switch *role_sw;
 	enum usb_role last_role;
 	struct regulator *vbus;
@@ -161,7 +165,17 @@ static int usb_conn_psy_register(struct usb_conn_info *info)
 		.fwnode = dev_fwnode(dev),
 	};
 
-	desc->name = "usb-charger";
+	info->conn_id = ida_alloc(&usb_conn_ida, GFP_KERNEL);
+	if (info->conn_id < 0)
+		return info->conn_id;
+
+	desc->name = devm_kasprintf(dev, GFP_KERNEL, "usb-charger-%d",
+				    info->conn_id);
+	if (!desc->name) {
+		ida_free(&usb_conn_ida, info->conn_id);
+		return -ENOMEM;
+	}
+
 	desc->properties = usb_charger_properties;
 	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
 	desc->get_property = usb_charger_get_property;
@@ -169,8 +183,10 @@ static int usb_conn_psy_register(struct usb_conn_info *info)
 	cfg.drv_data = info;
 
 	info->charger = devm_power_supply_register(dev, desc, &cfg);
-	if (IS_ERR(info->charger))
-		dev_err(dev, "Unable to register charger\n");
+	if (IS_ERR(info->charger)) {
+		dev_err(dev, "Unable to register charger %d\n", info->conn_id);
+		ida_free(&usb_conn_ida, info->conn_id);
+	}
 
 	return PTR_ERR_OR_ZERO(info->charger);
 }
@@ -278,6 +294,9 @@ static void usb_conn_remove(struct platform_device *pdev)
 
 	cancel_delayed_work_sync(&info->dw_det);
 
+	if (info->charger)
+		ida_free(&usb_conn_ida, info->conn_id);
+
 	if (info->last_role == USB_ROLE_HOST && info->vbus)
 		regulator_disable(info->vbus);
 

---
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
change-id: 20250411-work-next-d817787d63f2

Best regards,
-- 
Chance Yang <chance.yang@kneron.us>

Re: [PATCH v3] usb: common: usb-conn-gpio: use a unique name for usb connector device

[Greg Kroah-Hartman]

On Fri, Apr 11, 2025 at 04:33:26PM +0800, Chance Yang wrote:
> The current implementation of the usb-conn-gpio driver uses a fixed
> "usb-charger" name for all USB connector devices. This causes conflicts
> in the power supply subsystem when multiple USB connectors are present,
> as duplicate names are not allowed.
> 
> Use IDA to manage unique IDs for naming usb connectors (e.g.,
> usb-charger-0, usb-charger-1).
> 
> Fixes: 880287910b189 ("usb: common: usb-conn-gpio: fix NULL pointer dereference of charger")

This isn't a "fix" it is a "new feature to support multiple devices in
the same system".

So I'll drop the stable stuff here when applying it, thanks.

greg k-h