[Intel-gfx] [PATCH] drm/i915: Reduce a pin-leak BUG into a WARN

[Chris Wilson]

Pin-leaks persist and we get the perennial bug reports of machine
lockups to the BUG_ON(pin_count==MAX). If we instead loudly report that
the object cannot be pinned at that time it should prevent the driver from
locking up, and hopefully restore a semblance of working whilst still
leaving us a OOPS to debug.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index da17b40..58a5f6a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3555,7 +3555,8 @@ i915_gem_object_pin(struct drm_i915_gem_object *obj,
 {
 	int ret;
 
-	BUG_ON(obj->pin_count == DRM_I915_GEM_OBJECT_MAX_PIN_COUNT);
+	if (WARN_ON(obj->pin_count == DRM_I915_GEM_OBJECT_MAX_PIN_COUNT))
+		return -EBUSY;
 
 	if (obj->gtt_space != NULL) {
 		if ((alignment && obj->gtt_offset & (alignment - 1)) ||
-- 
1.7.10.4