[Intel-gfx] [PATCH] drm/i915: Print the condition causing GEM_BUG_ON

[Mika Kuoppala]

It is easier to categorize and debug bugs if the failed condition
is in plain sight in the actual dmesg output. Make it so.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h
index ee54597465b6..37ddc3f1f194 100644
--- a/drivers/gpu/drm/i915/i915_gem.h
+++ b/drivers/gpu/drm/i915/i915_gem.h
@@ -28,7 +28,10 @@
 #include <linux/bug.h>
 
 #ifdef CONFIG_DRM_I915_DEBUG_GEM
-#define GEM_BUG_ON(expr) BUG_ON(expr)
+#define GEM_BUG_ON(condition) do { if (unlikely(condition)) { \
+		printk(KERN_ERR "GEM_BUG: %s\n", __stringify(condition)); BUG(); \
+		} \
+	} while(0)
 #define GEM_WARN_ON(expr) WARN_ON(expr)
 
 #define GEM_DEBUG_DECL(var) var
-- 
2.11.0