Re: [PATCH 35/43] drm/i915: Move __raw_i915_read8() & co. into i915_drv.h

Ville Syrjälä
2015-09-18T18:23:14Z

On Fri, Sep 18, 2015 at 06:42:17PM +0100, Chris Wilson wrote:
> On Fri, Sep 18, 2015 at 08:03:48PM +0300, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > We have a few users of the raw register acces functions outside
> > intel_uncore.c, so let's just move the functions into intel_drv.h.
>
> I would rather see those external users converted to
> I915_READ_FW/I915_WRITE_FW etc. You will then, no doubt, want to convert
> those _FW macro definitions over to the uncore set.
>
> Also due to how we write and post our accesses, the raw functions can be
> the _relaxed variants.

Hmm. I think the only difference with the relaxed vs. not would be
potential compiler reordering of memory accesses vs. mmio. So if we
start using the relaxed versions we may need to start sprinkling
barriers around.

--
Ville Syrjälä
Intel OTC