[PATCH 2/3] drm: Make drm_gem_fb_alloc available for drivers to use

[Alexandru-Cosmin Gheorghe]

On Wed, Aug 15, 2018 at 01:54:12PM +0200, Daniel Vetter wrote:
> On Wed, Aug 15, 2018 at 12:08:38PM +0100, Liviu Dudau wrote:
> > On Thu, Jul 26, 2018 at 03:10:04PM +0100, Alexandru Gheorghe wrote:
> > > Some drivers can't use drm_gem_fb_create, so instead of copying the
> > > logic that does the framebuffer allocation allow them to use core
> > > drm_gem_fb_alloc.
> > > 
> > > Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe at arm.com>
> > 
> > To me it looks like an useful thing to have exported, so for what is worth:
> > 
> > Acked-by: Liviu Dudau <liviu.dudau at arm.com>
> > 
> > Sean, Maarten, Laurent, Gustavo, Daniel(s), do you have any objections?
> 
> In general please add meaningful kernel-doc for exported functions,
> explaing what's different and how it works together.
> 
> Wrt the specific issue, I think we should teach drm core and helpers how
> to allocate formats with tiled blocks. Means we need to extend
> drm_format_info a bit. Your YUV formats won't be the only ones where the
> format itself arranges pixels in blocks, and hence has format-based
> alignment criteria for pitch and size (due to line rounding).

Something like a tile_size or do you have other ideas ? 
Any idea if there are any tile formats out there where the tile it's
not a square ?

> 
> I think this would also fit better into the overall design where drivers
> can overwrite the drm_format_info for specific (fourcc, modifier)
> combinations.
> -Daniel
> 
> 
> > 
> > Best regards,
> > Liviu
> > 
> > > ---
> > >  drivers/gpu/drm/drm_gem_framebuffer_helper.c | 3 ++-
> > >  include/drm/drm_gem_framebuffer_helper.h     | 5 +++++
> > >  2 files changed, 7 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> > > index 2810d4131411..64eddf5a1bd9 100644
> > > --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> > > +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> > > @@ -57,7 +57,7 @@ struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
> > >  }
> > >  EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
> > >  
> > > -static struct drm_framebuffer *
> > > +struct drm_framebuffer *
> > >  drm_gem_fb_alloc(struct drm_device *dev,
> > >  		 const struct drm_mode_fb_cmd2 *mode_cmd,
> > >  		 struct drm_gem_object **obj, unsigned int num_planes,
> > > @@ -85,6 +85,7 @@ drm_gem_fb_alloc(struct drm_device *dev,
> > >  
> > >  	return fb;
> > >  }
> > > +EXPORT_SYMBOL_GPL(drm_gem_fb_alloc);
> > >  
> > >  /**
> > >   * drm_gem_fb_destroy - Free GEM backed framebuffer
> > > diff --git a/include/drm/drm_gem_framebuffer_helper.h b/include/drm/drm_gem_framebuffer_helper.h
> > > index a38de7eb55b4..d20c1356000a 100644
> > > --- a/include/drm/drm_gem_framebuffer_helper.h
> > > +++ b/include/drm/drm_gem_framebuffer_helper.h
> > > @@ -14,6 +14,11 @@ struct drm_simple_display_pipe;
> > >  
> > >  struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
> > >  					  unsigned int plane);
> > > +struct drm_framebuffer *
> > > +drm_gem_fb_alloc(struct drm_device *dev,
> > > +		 const struct drm_mode_fb_cmd2 *mode_cmd,
> > > +		 struct drm_gem_object **obj, unsigned int num_planes,
> > > +		 const struct drm_framebuffer_funcs *funcs);
> > >  void drm_gem_fb_destroy(struct drm_framebuffer *fb);
> > >  int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
> > >  			     unsigned int *handle);
> > > -- 
> > > 2.18.0
> > > 
> > 
> > -- 
> > ====================
> > | I would like to |
> > | fix the world,  |
> > | but they're not |
> > | giving me the   |
> >  \ source code!  /
> >   ---------------
> >     ¯\_(ツ)_/¯
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Cheers,
Alex G