[Intel-gfx] [PATCH 2/2] drm/i915: Don't BUG_ON in i915_gem_obj_offset

[Daniel Vetter]

A WARN_ON is perfectly fine.

The BUG in here seems to be the cause behind hard-hangs when I cat the
i915_gem_pageflip debugfs file (which calls this from an irq
spinlock). But only while running a full igt run after a while. I
still need to root cause the underlying issue.

I'll also start reject patches which add new BUG_ON but don't come
with a really good justification for it. The general rule really
should be to just WARN and hope the driver survives for long enough.

Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 35b5027ba5a4..841e9cd38dc1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5101,7 +5101,7 @@ unsigned long i915_gem_obj_offset(struct drm_i915_gem_object *o,
 	    vm == &dev_priv->mm.aliasing_ppgtt->base)
 		vm = &dev_priv->gtt.base;
 
-	BUG_ON(list_empty(&o->vma_list));
+	WARN_ON(list_empty(&o->vma_list));
 	list_for_each_entry(vma, &o->vma_list, vma_link) {
 		if (vma->vm == vm)
 			return vma->node.start;
-- 
1.8.1.4