Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev

[Arnd Bergmann]

On Thursday 28 April 2016 15:16:12 Russell King - ARM Linux wrote:
> On Thu, Apr 28, 2016 at 09:37:08AM +0300, Felipe Balbi wrote:
> > 
> > Hi,
> > 
> > Arnd Bergmann <arnd@xxxxxxxx> writes:
> > >    pointer and pass that in platform_data. This is really easy, it's
> > 
> > Sorry but passing a struct device pointer in platform_data is
> > ridiculous. Not to mention that, as I said before, we can't assume which
> > device to pass to xhci_plat in the first place. It might be dwc->dev and
> > it might be dwc->dev->parent.
> 
> +1.  Passing an unref-counted struct device through platform data is
> totally mad, Arnd you're off your rocker if you think that's a good
> idea.  What's more is that there's no way to properly refcount the
> thing.

It's the parent device (or NULL), there is no way it can ever go away as
it's already refcounted through the device subsystem by the creation
of the child device.

I do realize that it's a hack, but the idea is to get rid of that
as soon as possibly by fixing the way the xhci device is probe so
we no longer need to fake a platform_device as the child here and
can just use the device itself.

	Arnd