[PATCH 4/6] staging: vc04_services: Remove dmac_map_area

[Michael Zoran]

On Wed, 2016-10-19 at 13:41 +0200, Greg KH wrote:
> On Wed, Oct 19, 2016 at 01:37:30AM -0700, Michael Zoran wrote:
> > > From 8084d0832baf89990adef43a62801fccde20d0d8 Mon Sep 17 00:00:00
> > > 2001
> > 
> > F
> > rom: Michael Zoran <mzoran at crowfest.net>
> > Date: Wed, 19 Oct 2016 00:54:11
> > -0700
> > Subject: [PATCH 4/6] staging: vc04_services: Remove dmac_map_area
> > 
> > T
> > he arm specific code of VCHIQ uses dmac_map_area which is
> > not currently
> > supported on arm64.  This change adds
> > an architecture neutral
> > replacement based on
> > dma_map_page that does not use this feature.
> 
> From what I can read in this email, I like the patch, but have you
> noticed any performance issues?  I know the comment says they are
> doing
> this "for a good reason", but is there really one?
> 
> thanks,
> 
> greg k-h

It's a bit hard to tell.  As far as I know, only a few things actually
use the vchiq driver.  

One is HDMI audio which by default uses control messages instead of
bulk so it doesn't use this specific code path.

The other is some of the multimedia stuff.  Since I haven't bought the
multimedia license and don't have the offical camera, it's a bit hard
to run a "real world" benchmark.

It anybody has any ideas on what else to run for benchmarking, I'm
certainly willing to do it.