[Intel-gfx] [PATCH] drm/i915: Limit Valleyview and earlier to only using mappable scanout

[Chris Wilson]

On Fri, Nov 04, 2016 at 12:59:08PM +0000, Tvrtko Ursulin wrote:
> 
> On 04/11/2016 11:08, Chris Wilson wrote:
> >Valleyview and Cherryview are definitely limited to only scanning out
> >from the first 256MiB and 512MiB of the Global GTT respectively. Lets
> >presume that this behaviour was inherited from the display block copied
> >from g4x (not Ironlake) and all earlier generations are similarly
> >affected. For simplicity, impose that these platforms must scanout from
> >the mappable region.
> >
> >Reported-by: Luis Botello <luis.botello.ortega at intel.com>
> >Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98036
> >Fixes: 2efb813d5388 ("drm/i915: Fallback to using unmappable memory for scanout")
> >Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> >Cc: Akash Goel <akash.goel at intel.com>
> >Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> >Cc: <drm-intel-fixes at lists.freedesktop.org> # v4.9-rc1+
> >---
> >This leaves Ironlake -> Haswell with a bit of uncertainity. It is also
> >not clear if the scanout accessible region is similarly limited on all
> >gen8+, and so whether we need to similarly curtain the upper range for
> >their scanouts.
> >---
> > drivers/gpu/drm/i915/i915_gem.c | 18 ++++++++++++++++--
> > 1 file changed, 16 insertions(+), 2 deletions(-)
> >
> >diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> >index 269e2487c104..408875fbec66 100644
> >--- a/drivers/gpu/drm/i915/i915_gem.c
> >+++ b/drivers/gpu/drm/i915/i915_gem.c
> >@@ -3661,8 +3661,22 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
> > 	if (view->type == I915_GGTT_VIEW_NORMAL)
> > 		vma = i915_gem_object_ggtt_pin(obj, view, 0, alignment,
> > 					       PIN_MAPPABLE | PIN_NONBLOCK);
> >-	if (IS_ERR(vma))
> >-		vma = i915_gem_object_ggtt_pin(obj, view, 0, alignment, 0);
> >+	if (IS_ERR(vma)) {
> >+		struct drm_i915_private *i915 = to_i915(obj->base.dev);
> 
> dev_priv ?
> 
> What do we do with i915_params being a global i915?

Sssh, I'm gradually waging war against dev_priv.
Eventually Jani won't be able to complain about i915 being the minority.

The global modparams is an easy rename.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre