usb: core: skip interfaces disabled in devicetree

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sat, Feb 16, 2019 at 05:04:52PM +0000, Mans Rullgard wrote:
> If an interface has an associated devicetree node with status disabled,
> do not register the device.  This is useful for boards with a built-in
> multifunction USB device where some functions are broken or otherwise
> undesired.
> 
> Signed-off-by: Mans Rullgard <mans@mansr.com>
> ---
>  drivers/usb/core/message.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index bfa5eda0cc26..6b45d4835e41 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -2007,6 +2007,10 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
>  	for (i = 0; i < nintf; ++i) {
>  		struct usb_interface *intf = cp->interface[i];
>  
> +		if (intf->dev.of_node &&
> +		    !of_device_is_available(intf->dev.of_node))
> +			continue;

Shouldn't you at least print some message out saying you are skipping
this?  Odds are this is going to cause regressions in devices that were
not expecting this, right?  So pointing them at why their devices now no
longer work would be good :)

thanks,

greg k-h