Re: [PATCH 1/3] picolcd: driver for PicoLCD HID device

From: Alan Stern
Date: Sat Mar 13 2010 - 16:36:18 EST


On Sat, 13 Mar 2010, Bruno [UTF-8] Prémont wrote:

> Is something like below acceptable? (from error handling point of view
> it makes no difference...)
>
> Thanks,
> Bruno
>
> file: drivers/hid/hid-core.c
>
> int hid_add_device(struct hid_device *hdev)
> {
> static atomic_t id = ATOMIC_INIT(0);
> int ret;
>
> if (WARN_ON(hdev->status & HID_STAT_ADDED))
> return -EBUSY;
>
> /* we need to kill them here, otherwise they will stay allocated to
> * wait for coming driver */
> if (hid_ignore(hdev))
> return -ENODEV;
>
> /* XXX hack, any other cleaner solution after the driver core
> * is converted to allow more than 20 bytes as the device name? */
> dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
> hdev->vendor, hdev->product, atomic_inc_return(&id));
>
> + hid_debug_register(hdev, dev_name(&hdev->dev));
> ret = device_add(&hdev->dev);
> if (!ret)
> hdev->status |= HID_STAT_ADDED;
>
> - hid_debug_register(hdev, dev_name(&hdev->dev));
>
> return ret;
> }

If the device_add() fails, you should undo the hid_debug_register()
call.

Alan Stern

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