[Intel-gfx] [PATCH] drm/i915/gt: Ignore dt==0 for reporting underflows

[Chris Wilson]

The presumption was that some time would always elapse between recording
the start and the finish of a context switch. This turns out to be a
regular occurrence and emitting a debug statement superfluous.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 287537089c77..d288d92e2cd9 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1307,7 +1307,7 @@ static void reset_active(struct i915_request *rq,
 static void st_update_runtime_underflow(struct intel_context *ce, s32 dt)
 {
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
-	ce->runtime.num_underflow += dt < 0;
+	ce->runtime.num_underflow++;
 	ce->runtime.max_underflow = max_t(u32, ce->runtime.max_underflow, -dt);
 #endif
 }
@@ -1324,7 +1324,7 @@ static void intel_context_update_runtime(struct intel_context *ce)
 	ce->runtime.last = intel_context_get_runtime(ce);
 	dt = ce->runtime.last - old;
 
-	if (unlikely(dt <= 0)) {
+	if (unlikely(dt < 0)) {
 		CE_TRACE(ce, "runtime underflow: last=%u, new=%u, delta=%d\n",
 			 old, ce->runtime.last, dt);
 		st_update_runtime_underflow(ce, dt);
-- 
2.20.1