[Intel-gfx] [PATCH 2/7] drm/i915: On GPU reset, set the HWS breadcrumb to the last seqno

[Joonas Lahtinen]

On ke, 2016-04-06 at 00:57 +0100, Chris Wilson wrote:
> After the GPU reset and we discard all of the incomplete requests, mark
> the GPU as having advanced to the last_submitted_seqno (as having
> completed the requests and ready for fresh work). The impact of this is
> negligible, as all the requests will be considered completed by this
> point, it just brings the HWS into line with expectations for external
> viewers.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Makes sense to me.

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_gem.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 40f90c7e718a..3e9e6f9b66f5 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2882,6 +2882,8 @@ static void i915_gem_reset_engine_cleanup(struct drm_i915_private *dev_priv,
>  		buffer->last_retired_head = buffer->tail;
>  		intel_ring_update_space(buffer);
>  	}
> +
> +	intel_ring_init_seqno(engine, engine->last_submitted_seqno);
>  }
>  
>  void i915_gem_reset(struct drm_device *dev)
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation