Re: [RFC 0/2] USB gadget - configfs

[Joel Becker]

On Mon, Aug 20, 2012 at 01:01:03PM +0200, Sebastian Andrzej Siewior wrote:
> On 08/20/2012 07:59 AM, Joel Becker wrote:
> >	I think what you want here is a symlink.  Create a directory
> >high in the tree called 'ready' or 'available', and when you want to
> >lock the device in place, symlink it into that directory.  This will pin
> >the item.  You can also make use of the ->allow_link() and ->drop_link()
> >callbacks to prevent symlinking an item until it is fully configured,
> >and prevent unlinking an item that is in use.
> >
> >   $ ln -s /cfg/usb-function-gadget/G1/C1/F1/f_mass_storage/lun0 \
> >         /cfg/usb-function-gadget/ready/
> >
> >or something like that.
> 
> That would be something like
> 
>   $ ln -s /cfg/usb-function-gadget/G1 \
>         /cfg/usb-function-gadget/udcs/udc1/
> 
> Where we "bind" the complete gadget (G1) including the mass storage
> configuration to the UDC (udc1 in this example).
> 
> At this point we could snapshot the complete configuration so we have
> it persistent and if somebody changes attributes within /cfg/usb-
> function-gadget/G1 it doesn't matter because we have the copy.
> 
> Is it _this_ what you want us to do? A snapshot?

	No, I don't see why you would snapshot.  You can, btw, reject
->store_attribute() operations once you are in a "ready" state.  That's
different from preventing the removal of items.

Joel


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			http://www.jlbec.org/
			jlbec@xxxxxxxxxxxx
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