Re: [PATCH] drm/i915: clarify IS_GEN vs IS_<product> usage

[Chris Wilson <chris@chris-wilson.co.uk>]

On Tue, 10 May 2011 11:45:54 -0700, Eric Anholt <eric@anholt.net> wrote:
> On Mon, 9 May 2011 11:42:13 -0700, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> This feels like a lot of churn to me, for the pre-gen4 chipsets at
> least.  gen2 is always is_830_display (which is overly specific), and
> gen3 is always is_i915_display.

The argument is that we want to be consistent in how we test for
capabilities so that adding new feature tests or new chipsets is easier
and has no side-effects with existing capabilities. How the macros map
on to the actual devices is another matter - a compromise between
simplicity and runtime efficiency.

If it doesn't reduce our long term maintenance burden, then there is
no point making the distinction. I think more fine-grained checks will
help in the future, (and consistency across all generations prevents silly
bugs).

I'm still skeptical that the segregation of capabilities between
chipset/display/render is as clear cut as Jesse portrays. ;-)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre