[Intel-gfx] [PATCH 3/7] drm/i915: set num_fence_regs to 0 if there is no aperture

[Daniele Ceraolo Spurio]

On 10/29/19 2:58 AM, Matthew Auld wrote:
> From: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> 
> We can't fence anything without aperture.
> 
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Signed-off-by: Stuart Summers <stuart.summers at intel.com>
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem_fence_reg.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_fence_reg.c b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> index 321189e1b0f2..71efccfde122 100644
> --- a/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> +++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> @@ -846,8 +846,10 @@ void i915_ggtt_init_fences(struct i915_ggtt *ggtt)
>   
>   	detect_bit_6_swizzle(ggtt);
>   
> -	if (INTEL_GEN(i915) >= 7 &&
> -	    !(IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)))
> +	if (!i915_ggtt_has_aperture(ggtt))

Daniel had mentioned that the fencing HW has been nerfed in gen12 and 
suggested settings num_fences to zero for all gen12+. Should we go 
directly with that?

Daniele

> +		num_fences = 0;
> +	else if (INTEL_GEN(i915) >= 7 &&
> +		 !(IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)))
>   		num_fences = 32;
>   	else if (INTEL_GEN(i915) >= 4 ||
>   		 IS_I945G(i915) || IS_I945GM(i915) ||
>