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

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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: 249fa8217b84 ("USB: Add driver to control USB fast charge for iOS devices")
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Link: https://lore.kernel.org/r/20250602-apple-mfi-fastcharge-duplicate-sysfs-v1-1-5d84de34fac6@posteo.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Charalampos Mitrodimas 2025-06-02 18:26:17 +00:00 committed by Greg Kroah-Hartman
parent 1f25307c90
commit 43007b89fb
1 changed files with 21 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/usb/misc/apple-mfi-fastcharge.c
View File

@ -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);