Re: [PATCH v2 16/18] drm/i915: Check against correct user_size limit in 48b ppgtt mode

Chris Wilson
2015-06-10T17:57:56Z

On Wed, Jun 10, 2015 at 05:46:53PM +0100, Michel Thierry wrote:
> GTT is only 32b and its max value is 4GB. In order to allow objects
> bigger than 4GB in 48b PPGTT, i915_gem_userptr_ioctl needs to check
> against max 48b range (1ULL << 48).
>
> Whenever possible, read the PPGTT's total instead of the GTT one, this
> will be accurate in 32 and 48 bit modes.

Just kill the limit. It is only there for early detection of an error
when it is used for execbuffer - however, we may be using the bo for
other purposes where the limit doesn't apply. Or the check may be
invalid (such as now).
-Chris

--
Chris Wilson, Intel Open Source Technology Centre