[Intel-gfx] [PATCH] drm/i915/perf: Refactor oa object to better manage resources

[Umesh Nerlige Ramappa]

On Tue, May 14, 2019 at 10:34:49AM +0100, Lionel Landwerlin wrote:
>Hi Umesh,
>
>I just noticed this different between v1 & v2.
>My understanding is that if destroy() is called, stream should be the 
>same as dev_priv->perf.exclusive_stream.
>If it's not it sounds like a bug. So why change this?
>
v2 fixes only checkpatch warnings. it warned on use of BUG_ON. BUG_ON is 
intended to crash the system in severe cases where the driver/kernel is 
unusable. In this case, the mismatch between user passed information and 
exclusive_stream may not require a crash.
>-Lionel
>
>On 03/05/2019 00:13, Umesh Nerlige Ramappa wrote:
>>  static void i915_oa_stream_destroy(struct i915_perf_stream *stream)
>>  {
>>  	struct drm_i915_private *dev_priv = stream->dev_priv;
>>-	BUG_ON(stream != dev_priv->perf.oa.exclusive_stream);
>>+	if (stream != dev_priv->perf.exclusive_stream) {
>>+		WARN_ON_ONCE(stream != dev_priv->perf.exclusive_stream);
>>+		return;
>>+	}
>>  	/*
>
>