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Date:   Tue, 16 Oct 2018 08:29:24 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Roman Kiryanov <rkir@google.com>
Cc:     linux-kernel@vger.kernel.org, Todd Kjos <tkjos@google.com>
Subject: Re: [PATCH v3 09/15] platform: goldfish: pipe: Move goldfish_pipe to
 goldfish_pipe_v2
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On Mon, Oct 15, 2018 at 01:23:35PM -0700, Roman Kiryanov wrote:
> > > I want our "v2" driver to be in a "v2" file and our "v1" driver in a
> > > "v1" file. I think this is reasonable.
> >
> > The in kernel driver is the "v1" one.
> 
> I believe v2 (on our end) was upstream as goldfish_pipe.c instead of
> goldfish_pipe_v2.c.

I do not understand this, sorry.  My point of view is the in-kernel
code, I know nothing about out-of-tree code, nor do I care :)

> >  Why do you need a totally new driver file at all anyway?
> 
> I don't want to mix v1 and v2.

Why?  What is the difference?  Why do you even need/want 2 different
drivers here for something that really should be done with the virtio
interface instead?

> > And again, can you GUARANTEE that userspace will not break if you rename
> > the kernel module?
> 
> Yes, it works:
> https://android.googlesource.com/kernel/goldfish/+/android-goldfish-4.14-dev/drivers/platform/goldfish/

That's a kernel, not userspace, code.

> I don't see how userspace could be affected, unless we refer to
> __FILE__ inside the driver for some important things. I believe we
> don't.

How does your userspace know what module to automatically load?  That's
what usually breaks if you do not have proper platform binding happening
automatically.

thanks,

greg k-h