Re: [PATCHv3 1/5] usb: gadget: bind UDC by name passed via usb_gadget_driver structure

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 2/18/2015 12:17 AM, Ruslan Bilovol wrote:

> Introduce new 'udc_name' member to usb_gadget_driver structure.
> The 'udc_name' is a name of UDC that usb_gadget_driver should
> be bound to. If udc_name is NULL, it will be bound to any
> available UDC.

> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
> ---
>   drivers/usb/gadget/udc/udc-core.c | 25 ++++++++++++++++++++-----
>   include/linux/usb/gadget.h        |  4 ++++
>   2 files changed, 24 insertions(+), 5 deletions(-)

> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> index 5a81cb0..e1079e08 100644
> --- a/drivers/usb/gadget/udc/udc-core.c
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -440,21 +440,36 @@ EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
>   int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
>   {
>   	struct usb_udc		*udc = NULL;
> -	int			ret;
> +	int			ret = -ENODEV;
>
>   	if (!driver || !driver->bind || !driver->setup)
>   		return -EINVAL;
>
>   	mutex_lock(&udc_lock);
> -	list_for_each_entry(udc, &udc_list, list) {
> -		/* For now we take the first one */
> -		if (!udc->driver)
> +	if (driver->udc_name) {
> +		list_for_each_entry(udc, &udc_list, list) {
> +			ret = strcmp(driver->udc_name, dev_name(&udc->dev));
> +			if (!ret)
> +				break;
> +		}
> +		if (ret)
> +			ret = -ENODEV;
> +		else if (udc->driver)
> +			ret = -EBUSY;
> +		else
>   			goto found;
> +	} else {
> +		list_for_each_entry(udc, &udc_list, list) {
> +			/* For now we take the first one */
> +			if (!udc->driver)
> +				goto found;
> +		}
> +		ret = -ENODEV;

    Already assigned the same value by the initializer.

>   	}
>
>   	pr_debug("couldn't find an available UDC\n");
>   	mutex_unlock(&udc_lock);
> -	return -ENODEV;
> +	return ret;
>   found:
>   	ret = udc_bind_to_driver(udc, driver);
>   	mutex_unlock(&udc_lock);
[...]

WBR, Sergei