[Intel-gfx] [PATCH 5/5] drm/i915: Clear the last_retired_context following a hang/reset

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> Following a hang and reset, we know that the engine is idle and all
> context state has been saved or lost. Consequently, we know that the
> engine is no longer referencing the last context and we can relinquish
> our tracking.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com>

> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> Cc: Tvrtko Ursulin <tursulin at ursulin.net>
> ---
>  drivers/gpu/drm/i915/i915_gem.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 730804ce9610..638b335e72b6 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2788,8 +2788,14 @@ void i915_gem_reset(struct drm_i915_private *dev_priv)
>  
>  	i915_gem_retire_requests(dev_priv);
>  
> -	for_each_engine(engine, dev_priv, id)
> +	for_each_engine(engine, dev_priv, id) {
> +		struct i915_gem_context *ctx;
> +
>  		i915_gem_reset_engine(engine);
> +		ctx = fetch_and_zero(&engine->last_retired_context);
> +		if (ctx)
> +			engine->context_unpin(engine, ctx);
> +	}
>  
>  	i915_gem_restore_fences(dev_priv);
>  
> -- 
> 2.11.0