[Intel-gfx] [PATCH 02/11] drm/i915: Only reset hangcheck at the start of an activity cycle

[Mika Kuoppala]

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

> Across a reset, the seqno (and thus hangcheck) should restart and the
> hangcheck naturally progress, for when it does not, we want to declare an
> emergency. Currently, we only detect if reset and reinit fails, but we
> do not detect if the call to reinit succeeds but the HW is fried - as we
> are resetting hangcheck on initialisation the engine. Remove that and
> rely on the natural progress to reset the hangcheck timer.

I take it that the intention is not to give reset
any special leeway wrt to request completion. So
we now assume that reset/recovery must fit inside
one hangcheck tick?

-Mika


>
> References: e21b141376f9 ("drm/i915: Mark the hangcheck as idle when unparking the engines")
> References: 1fd00c0faeec ("drm/i915: Declare the driver wedged if hangcheck makes no progress")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_lrc.c        | 1 -
>  drivers/gpu/drm/i915/intel_ringbuffer.c | 2 --
>  2 files changed, 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index ab89dabc2965..933495996e91 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -1852,7 +1852,6 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
>  		return ret;
>  
>  	intel_engine_reset_breadcrumbs(engine);
> -	intel_engine_init_hangcheck(engine);
>  
>  	if (GEM_SHOW_DEBUG() && unexpected_starting_state(engine)) {
>  		struct drm_printer p = drm_debug_printer(__func__);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 700f94c371b3..f4bd185c9369 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -524,8 +524,6 @@ static int init_ring_common(struct intel_engine_cs *engine)
>  		goto out;
>  	}
>  
> -	intel_engine_init_hangcheck(engine);
> -
>  	if (INTEL_GEN(dev_priv) > 2)
>  		I915_WRITE_MODE(engine, _MASKED_BIT_DISABLE(STOP_RING));
>  
> -- 
> 2.18.0