Re: [Intel-gfx] [PATCH 1/2] drm/i915: Fix assert in i915_ggtt_pin

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Feb 25, 2022 at 05:41:17PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> 
> Use lockdep_assert_not_held to simplify and correct the code. Otherwise
> false positive are hit if lock state is uknown like after a previous
> taint.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_vma.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index 3558b16a929c..4469b7f52853 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -1552,9 +1552,7 @@ int i915_ggtt_pin(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
>  	if (ww)
>  		return __i915_ggtt_pin(vma, ww, align, flags);
>  
> -#ifdef CONFIG_LOCKDEP
> -	WARN_ON(dma_resv_held(vma->obj->base.resv));
> -#endif
> +	lockdep_assert_not_held(&vma->obj->base.resv->lock.base);

Should there be a dma_resv wrapper for that? Shrug.

Makes sense to me:
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

I'll leave the other one to someone how knows how it's actually used.

>  
>  	for_i915_gem_ww(&_ww, err, true) {
>  		err = i915_gem_object_lock(vma->obj, &_ww);
> -- 
> 2.32.0

-- 
Ville Syrjälä
Intel