[Intel-gfx] [PATCH] drm/i915: Remove incorrect warning in context cleanup

[Daniel Vetter]

On Fri, Nov 20, 2015 at 01:23:36PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Commit e9f24d5fb7cf3628b195b18ff3ac4e37937ceeae
> Author: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Date:   Mon Oct 5 13:26:36 2015 +0100
> 
>     drm/i915: Clean up associated VMAs on context destruction
> 
> Added a warning based on an incorrect assumption that all VMAs
> in a VM will be on the inactive list at the point last reference
> to a context and VM is dropped.
> 
> This is not true because i915_gem_object_retire__read will not
> put VMA on the inactive list until all activities on the object
> in question (in all VMs) have been retired.
> 
> As a consequence, whether or not a context/VM will be destroyed
> with its VMAs still on the active list, can depend on completely
> unrelated activities using the same object from a different
> context or engine.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92638
> Testcase: igt/gem_request_retire/retire-vma-not-inactive
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michel Thierry <michel.thierry at intel.com>

Queued for -next, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem_context.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index 204dc7c0b2d6..59dba318213e 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -141,8 +141,6 @@ static void i915_gem_context_clean(struct intel_context *ctx)
>  	if (!ppgtt)
>  		return;
>  
> -	WARN_ON(!list_empty(&ppgtt->base.active_list));
> -
>  	list_for_each_entry_safe(vma, next, &ppgtt->base.inactive_list,
>  				 mm_list) {
>  		if (WARN_ON(__i915_vma_unbind_no_wait(vma)))
> -- 
> 1.9.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch