Commit 43007b89 authored by Charalampos Mitrodimas's avatar Charalampos Mitrodimas Committed by Greg Kroah-Hartman
Browse files

usb: misc: apple-mfi-fastcharge: Make power supply names unique 



When multiple Apple devices are connected concurrently, the
apple-mfi-fastcharge driver fails to probe the subsequent devices with
the following error:

    sysfs: cannot create duplicate filename '/class/power_supply/apple_mfi_fastcharge'
    apple-mfi-fastcharge 5-2.4.3.3: probe of 5-2.4.3.3 failed with error -17

This happens because the driver uses a fixed power supply name
("apple_mfi_fastcharge") for all devices, causing a sysfs name
conflict when a second device is connected.

Fix this by generating unique names using the USB bus and device
number (e.g., "apple_mfi_fastcharge_5-12"). This ensures each
connected device gets a unique power supply entry in sysfs.

The change requires storing a copy of the power_supply_desc structure
in the per-device mfi_device struct, since the name pointer needs to
remain valid for the lifetime of the power supply registration.

Fixes: 249fa821 ("USB: Add driver to control USB fast charge for iOS devices")
Signed-off-by: default avatarCharalampos Mitrodimas <charmitro@posteo.net>
Link: https://lore.kernel.org/r/20250602-apple-mfi-fastcharge-duplicate-sysfs-v1-1-5d84de34fac6@posteo.net


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1f25307c

drivers/usb/misc/apple-mfi-fastcharge.c

+21 −3
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ MODULE_DEVICE_TABLE(usb, mfi_fc_id_table); 
struct mfi_device {

	struct usb_device *udev;

	struct power_supply *battery;

	struct power_supply_desc battery_desc;

	int charge_type;

};
@@ -178,6 +179,7 @@ static int mfi_fc_probe(struct usb_device *udev) 
{

	struct power_supply_config battery_cfg = {};

	struct mfi_device *mfi = NULL;

	char *battery_name;

	int err;



	if (!mfi_fc_match(udev))
@@ -187,23 +189,38 @@ static int mfi_fc_probe(struct usb_device *udev) 
	if (!mfi)

		return -ENOMEM;



	battery_name = kasprintf(GFP_KERNEL, "apple_mfi_fastcharge_%d-%d",

				 udev->bus->busnum, udev->devnum);

	if (!battery_name) {

		err = -ENOMEM;

		goto err_free_mfi;

	}



	mfi->battery_desc = apple_mfi_fc_desc;

	mfi->battery_desc.name = battery_name;



	battery_cfg.drv_data = mfi;



	mfi->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;

	mfi->battery = power_supply_register(&udev->dev,

						&apple_mfi_fc_desc,

						&mfi->battery_desc,

						&battery_cfg);

	if (IS_ERR(mfi->battery)) {

		dev_err(&udev->dev, "Can't register battery\n");

		err = PTR_ERR(mfi->battery);

		kfree(mfi);

		return err;

		goto err_free_name;

	}



	mfi->udev = usb_get_dev(udev);

	dev_set_drvdata(&udev->dev, mfi);



	return 0;



err_free_name:

	kfree(battery_name);

err_free_mfi:

	kfree(mfi);

	return err;

}



static void mfi_fc_disconnect(struct usb_device *udev)
@@ -213,6 +230,7 @@ static void mfi_fc_disconnect(struct usb_device *udev) 
	mfi = dev_get_drvdata(&udev->dev);

	if (mfi->battery)

		power_supply_unregister(mfi->battery);

	kfree(mfi->battery_desc.name);

	dev_set_drvdata(&udev->dev, NULL);

	usb_put_dev(mfi->udev);

	kfree(mfi);