Re: [PATCH v2 1/1] platform: goldfish: pipe: add devicetree bindings

[Christoffer Dall <christoffer.dall@linaro.org>]

On Wed, Nov 25, 2015 at 02:24:16PM -0600, Rob Herring wrote:
> On Wed, Nov 25, 2015 at 11:59:37AM -0800, Jin Qian wrote:
> > From: Greg Hackmann <ghackmann@google.com>
> > 
> > Signed-off-by: Greg Hackmann <ghackmann@google.com>
> > (cherry picked from commit 3c56d07eb796066530e93a40e74dea3bc59bf4cf)
> > Signed-off-by: Jin Qian <jinqian@android.com>
> > ---
> >  Documentation/devicetree/bindings/goldfish/pipe.txt | 17 +++++++++++++++++
> >  drivers/platform/goldfish/goldfish_pipe.c           | 10 +++++++++-
> >  2 files changed, 26 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/devicetree/bindings/goldfish/pipe.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/goldfish/pipe.txt b/Documentation/devicetree/bindings/goldfish/pipe.txt
> > new file mode 100644
> > index 0000000..6d3801e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/goldfish/pipe.txt
> > @@ -0,0 +1,17 @@
> > +Android Goldfish QEMU Pipe
> > +
> > +Andorid pipe virtual device generated by android emulator.
> 
> The binding may be trivial, but there's a bigger question of whether 
> this is the right long term direction. For example is upstream QEMU 
> going to take all the Android pipe stuff? Couldn't virtio be used here 
> as the transport?
> 
The Android Pipe is not a very likely candidate for upstream QEMU, no.
We are working on a TCG implementation of virtio-vsock
(http://qemu-project.org/Features/VirtioVsock) which we think should be
a suitable drop-in replacement for the Android pipe.  We have yet to
measure performance differences between the two, especially in the
context of 3D graphics, though.

But I wonder if that should really block this from being merged?  The
support may not be in QEMU but it's in the Android emulator and it would
be a less broken implementation with these patches in the kernel than
without, I think.

-Christoffer