[Intel-gfx] [PATCH 04/28] drm/i915/gt: Ignore dt==0 for reporting underflows

[Tvrtko Ursulin]

On 17/11/2020 11:30, Chris Wilson wrote:
> 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 8a51c1c3a091..52b84474f93a 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);
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko