Re: [PATCH v2 2/7] bus: Introduce firewall controller framework

[Greg KH]

On Fri, Feb 14, 2020 at 05:05:07PM +0100, Linus Walleij wrote:
> On Fri, Jan 31, 2020 at 10:06 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> 
> > Why do people want to abuse the platform bus so much?  If a device is on
> > a bus that can have such a controller, then it is on a real bus, use it!
> 
> I'm not saying it is a good thing, but the reason why it is (ab)used so
> much can be found in:
> drivers/of/platform.c
> 
> TL;DR: struct platform_device is the Device McDeviceFace and
> platform bus the Bus McBusFace used by the device tree parser since
> it is slightly to completely unaware of what devices it is actually
> spawning.

<snip>

Yeah, great explaination, and I understand.  DT stuff really is ok to be
on a platform bus, as that's what almost all of them are.

But, when you try to start messing around with things like this
"firewall" says it is doing, it's then obvious that this really isn't a
DT like thing, but rather you do have a bus involved with a controller
so that should be used instead.

Or just filter away the DT stuff so that the kernel never even sees
those devices, which might just be simplest :)

thanks,

greg k-h