From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Anholt <eric@anholt.net>
Subject: Re: [PATCH] drm/i915: Remove bogus test for a present
	execbuffer
Date: Mon, 19 Nov 2012 08:42:59 -0800
Message-ID: <874nkllf1o.fsf@eliezer.anholt.net>
References: <1353339042-23076-1-git-send-email-chris@chris-wilson.co.uk>
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Chris Wilson <chris@chris-wilson.co.uk> writes:

> The intention of checking obj->gtt_offset!=0 is to verify that the
> target object was listed in the execbuffer and had been bound into the
> GTT. This is guarranteed by the earlier rearrangement to split the
> execbuffer operation into reserve and relocation phases and then
> verified by the check that the target handle had been processed during
> the reservation phase.
>
> However, the actual checking of obj->gtt_offset==0 is bogus as we can
> indeed reference an object at offset 0. For instance, the framebuffer
> installed by the BIOS often resides at offset 0 - causing EINVAL as we
> legimately try to render using the stolen fb.

We've never triggered this check in practice, as far as I know, so I'm
happy to see it go.

Reviewed-by: Eric Anholt <eric@anholt.net>

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