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

[Tvrtko Ursulin]

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>
---
 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