[Intel-gfx] [PATCH 7/8] drm/i915: Make display gtt offsets u32

[Ville Syrjälä]

On Thu, Jan 14, 2016 at 10:36:53PM +0000, Chris Wilson wrote:
> On Thu, Jan 14, 2016 at 03:22:15PM +0200, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > Using 'unsigned long' for ggtt offsets doesn't make much sense. Use
> > 'u32' instead since we've not yet seen a >4GiB ggtt.
> 
> We should do:
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 2e460b369e82..2ce16acceb75 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -3143,6 +3143,13 @@ int i915_gem_gtt_init(struct drm_device *dev)
>         if (ret)
>                 return ret;
>  
> +       if (gtt->base.total >> 32) {
> +               DRM_ERROR("The code does not expect a Global GTT with more that 32bits of address space! Found %lldM!\n",
> +                         gtt->base.total >> 20);
> +               gtt->base.total = 1ull << 32;
> +               gtt->mappable_end = min(gtt->mappable_end, gtt->base.total);
> +       }
> +
>         /* GMADR is the PCI mmio aperture into the global GTT. */
>         DRM_INFO("Memory usable by graphics device = %lluM\n",
>                  gtt->base.total >> 20);
> 
> To get that early warning in.

Seems reasonable. Feel free to slap on
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> -Chris
> 
> -- 
> Chris Wilson, Intel Open Source Technology Centre

-- 
Ville Syrjälä
Intel OTC