Re: [PATCH 0/9 linux-next] drivers/gpu/drm: use container_of where possible

[Daniel Vetter]

On Mon, Sep 15, 2014 at 08:15:54PM +0200, Fabian Frederick wrote:
> 
> 
> > On 15 September 2014 at 01:13 One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>
> > wrote:
> >
> >
> > On Sun, 14 Sep 2014 18:40:13 +0200
> > Fabian Frederick <fabf@xxxxxxxxx> wrote:
> >
> > > Small patchset using container_of instead of casting on first structure
> > > member address.
> >
> > Why. Container_of is useful for random offsets but its just convoluting
> > and confusing code which is designed with the fields intentionally at the
> > start.
> >
> > Alan
> 
> What if someone doesn't know about that intention one day and inserts
> some field in the structure at the "wrong place" ?
> This would need at least some comment in each declaration
> but once again it's hard to control.One other way is to
> commonly use container_of and get rid of every casting with
> some semantic script.
> 
> Peter has been asking for container_of in the following:
> 
> http://marc.info/?l=linux-arm-kernel&m=140838705729653&w=2
> 
> 
> struct uart_amba_port *uap = (struct uart_amba_port *)port
> 
> (port/uart_port is the first field in uart_amba_port though)

fwiw I like this and I've picked it up into my topic/core-stuff branch. So
if driver writers don't outright nack this it'll all land in Dave's
drm-next (probably still for 3.18).
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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