[Intel-gfx] [PATCH v3] drm/i915: A hotfix for making aliasing PPGTT work

[Wang, Zhi A]

Thanks Jani! :P

-----Original Message-----
From: Jani Nikula [mailto:jani.nikula at linux.intel.com] 
Sent: Thursday, February 9, 2017 8:23 PM
To: Wang, Zhi A <zhi.a.wang at intel.com>; intel-gfx at lists.freedesktop.org
Cc: Wang, Zhi A <zhi.a.wang at intel.com>; Daniel Vetter <daniel.vetter at ffwll.ch>; Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>; Winiarski, Michal <michal.winiarski at intel.com>; Thierry, Michel <michel.thierry at intel.com>; Joonas Lahtinen <joonas.lahtinen at linux.intel.com>; Chris Wilson <chris at chris-wilson.co.uk>; Vetter, Daniel <daniel.vetter at intel.com>; Zhenyu Wang <zhenyuw at linux.intel.com>; Lv, Zhiyuan <zhiyuan.lv at intel.com>; drm-intel-fixes at lists.freedesktop.org
Subject: Re: [PATCH v3] drm/i915: A hotfix for making aliasing PPGTT work

On Thu, 09 Feb 2017, Zhi Wang <zhi.a.wang at intel.com> wrote:
> This patch makes PPGTT page table non-shrinkable when using aliasing 
> PPGTT mode. It's just a temporary solution for making aliasing PPGTT mode work.
>
> v3:
> - Fixes the format of "Fixes line".
>
> v2:
> - Add fixes tag. (Chris and Daniel)
>
> Fixes: 2ce5179fe826 ("drm/i915/gtt: Free unused lower-level page 
> tables")
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Cc: Michal Winiarski <michal.winiarski at intel.com>
> Cc: Michel Thierry <michel.thierry at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
> Cc: Zhiyuan Lv <zhiyuan.lv at intel.com>
> Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
> Link: 
> http://patchwork.freedesktop.org/patch/msgid/1486559013-25251-2-git-se
> nd-email-zhi.a.wang at intel.com
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: <drm-intel-fixes at lists.freedesktop.org> # v4.10-rc1+

This won't make it to v4.10, as I've sent the pull request already and I anticipate release this Sunday. Whoever applies this needs to add

Cc: stable at vger.kernel.org # v4.10

BR,
Jani.


> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c 
> b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 22b3374..3233f12 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -756,8 +756,10 @@ static bool gen8_ppgtt_clear_pt(struct 
> i915_address_space *vm,
>  
>  	bitmap_clear(pt->used_ptes, pte, num_entries);
>  
> -	if (bitmap_empty(pt->used_ptes, GEN8_PTES))
> -		return true;
> +	if (USES_FULL_PPGTT(vm->i915)) {
> +		if (bitmap_empty(pt->used_ptes, GEN8_PTES))
> +			return true;
> +	}
>  
>  	pt_vaddr = kmap_px(pt);

--
Jani Nikula, Intel Open Source Technology Center