drm/i915: Compile out engine debug for release

The majority of the engine state dumping is too voluminous to be useful
outside of a controlled setup, though a few do accompany severe errors.
Keep the debug dumps next to the errors, but hide the others behind a CI
compile flag. This becomes more useful when adding more dumps to latency
sensitive paths.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180426103219.22181-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem.c

@@ -3312,7 +3312,7 @@ void i915_gem_set_wedged(struct drm_i915_private *i915)
 
 	GEM_TRACE("start\n");
 
-	if (drm_debug & DRM_UT_DRIVER) {
+	if (GEM_SHOW_DEBUG()) {
 		struct drm_printer p = drm_debug_printer(__func__);
 
 		for_each_engine(engine, i915, id)

drivers/gpu/drm/i915/i915_gem.h

@@ -30,6 +30,9 @@
 struct drm_i915_private;
 
 #ifdef CONFIG_DRM_I915_DEBUG_GEM
+
+#define GEM_SHOW_DEBUG() (drm_debug & DRM_UT_DRIVER)
+
 #define GEM_BUG_ON(condition) do { if (unlikely((condition))) {	\
 		pr_err("%s:%d GEM_BUG_ON(%s)\n", \
 		       __func__, __LINE__, __stringify(condition)); \
@@ -45,6 +48,9 @@ struct drm_i915_private;
 #define GEM_DEBUG_BUG_ON(expr) GEM_BUG_ON(expr)
 
 #else
+
+#define GEM_SHOW_DEBUG() (0)
+
 #define GEM_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr)
 #define GEM_WARN_ON(expr) (BUILD_BUG_ON_INVALID(expr), 0)
 

drivers/gpu/drm/i915/intel_breadcrumbs.c

@@ -82,7 +82,7 @@ static unsigned long wait_timeout(void)
 
 static noinline void missed_breadcrumb(struct intel_engine_cs *engine)
 {
-	if (drm_debug & DRM_UT_DRIVER) {
+	if (GEM_SHOW_DEBUG()) {
 		struct drm_printer p = drm_debug_printer(__func__);
 
 		intel_engine_dump(engine, &p,

drivers/gpu/drm/i915/intel_hangcheck.c

@@ -356,7 +356,7 @@ static void hangcheck_accumulate_sample(struct intel_engine_cs *engine,
 		break;
 
 	case ENGINE_DEAD:
-		if (drm_debug & DRM_UT_DRIVER) {
+		if (GEM_SHOW_DEBUG()) {
 			struct drm_printer p = drm_debug_printer("hangcheck");
 			intel_engine_dump(engine, &p, "%s\n", engine->name);
 		}