[Intel-gfx] [PATCH 2/2] drm/i915/perf: Drop lockdep assert for i915_oa_init_reg_state()

[Lionel Landwerlin]

On 09/08/17 16:38, Chris Wilson wrote:
> This is called from execlist context init which we need to be unlocked.
> Commit f89823c21224 ("drm/i915/perf: Implement
> I915_PERF_ADD/REMOVE_CONFIG interface") added a lockdep assert to this
> path for unclear reasons, remove it again!
>
> Fixes: 701f8231a2fe ("drm/i915/perf: prune OA configs")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> Cc: Matthew Auld <matthew.auld at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_perf.c | 2 --
>   1 file changed, 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index 1be355d14e8a..3bdf53faae24 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -2173,8 +2173,6 @@ void i915_oa_init_reg_state(struct intel_engine_cs *engine,
>   	struct drm_i915_private *dev_priv = engine->i915;
>   	struct i915_perf_stream *stream = dev_priv->perf.oa.exclusive_stream;

I was trying to avoid adding a new lock for exclusive_stream.
If we can't rely on dev_priv->drm.struct_mutex to update 
exclusive_stream, I believe we need to add a new lock.
Or maybe some other mechanism?

>   
> -	lockdep_assert_held(&dev_priv->drm.struct_mutex);
> -
>   	if (engine->id != RCS)
>   		return;
>