[PATCH v3 01/22] drm: Add GEM backed framebuffer library

[Laurent Pinchart]

Hi Noralf,

One additional comment.

On Wednesday 16 Aug 2017 23:37:54 Laurent Pinchart wrote:
> On Sunday 13 Aug 2017 15:31:44 Noralf Trønnes wrote:
> > This library provides helpers for drivers that don't subclass
> > drm_framebuffer and are backed by drm_gem_object. The code is
> > taken from drm_fb_cma_helper.
> > 
> > Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> > Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> > ---
> > 
> >  Documentation/gpu/drm-kms-helpers.rst        |   9 +
> >  drivers/gpu/drm/Makefile                     |   2 +-
> >  drivers/gpu/drm/drm_gem_framebuffer_helper.c | 283 +++++++++++++++++++++
> >  include/drm/drm_framebuffer.h                |   7 +
> >  include/drm/drm_gem_framebuffer_helper.h     |  37 ++++
> >  5 files changed, 337 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/gpu/drm/drm_gem_framebuffer_helper.c
> >  create mode 100644 include/drm/drm_gem_framebuffer_helper.h
> 
> [snip]
> 
> > diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> > b/drivers/gpu/drm/drm_gem_framebuffer_helper.c new file mode 100644
> > index 0000000..068a630
> > --- /dev/null
> > +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> > @@ -0,0 +1,283 @@
> 
> [snip]
> 
> > +/**
> > + * DOC: overview
> > + *
> > + * This library provides helpers for drivers that don't subclass
> > + * &drm_framebuffer and and use &drm_gem_object for their backing
> > storage.
> 
> s/and and/and/
> 
> > + *
> > + * Drivers without additional needs to validate framebuffers can simply
> > use
> > + * drm_gem_fb_create() and everything is wired up automatically. But all
> > + * parts can be used individually.
> 
> A sentence should not start by "but". How about "Other drivers can use all
> parts independently." ?
> 
> > + */

We now have the GEM CMA helpers, the GEM FB helpers and the FB CMA helper. It 
starts getting very confusing for driver authors. The overview documentation 
should explain how they all interact and which helpers a driver can/should use 
in the different cases.

[snip]

-- 
Regards,

Laurent Pinchart