[Intel-gfx] [PATCH v6 14/20] drm/i915/guc: Add support for reset engine using GuC commands

[Chris Wilson]

On Tue, Apr 18, 2017 at 01:23:29PM -0700, Michel Thierry wrote:
> This patch adds per engine reset and recovery (TDR) support when GuC is
> used to submit workloads to GPU.
> 
> In the case of i915 directly submission to ELSP, driver manages hang
> detection, recovery and resubmission. With GuC submission these tasks
> are shared between driver and GuC. i915 is still responsible for detecting
> a hang, and when it does it only requests GuC to reset that Engine. GuC
> internally manages acquiring forcewake and idling the engine before actually
> resetting it.
> 
> Once the reset is successful, i915 takes over again and handles resubmission.
> The scheduler in i915 knows which requests are pending so after resetting
> a engine, pending workloads/requests are resubmitted again.
> 
> v2: s/i915_guc_request_engine_reset/i915_guc_reset_engine/ to match the
> non-guc funtion names.
> 
> Signed-off-by: Arun Siluvery <arun.siluvery at linux.intel.com>
> Signed-off-by: Jeff McGee <jeff.mcgee at intel.com>
> Signed-off-by: Michel Thierry <michel.thierry at intel.com>
> ---
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 7df278fe492e..6295760098a1 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -1176,14 +1176,15 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
>  
>  	/* After a GPU reset, we may have requests to replay */
>  	clear_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted);
> -	if (!i915.enable_guc_submission && !execlists_elsp_idle(engine)) {
> +	if (!execlists_elsp_idle(engine)) {
>  		DRM_DEBUG_DRIVER("Restarting %s from requests [0x%x, 0x%x]\n",
>  				 engine->name,
>  				 port_seqno(&engine->execlist_port[0]),
>  				 port_seqno(&engine->execlist_port[1]));
>  		engine->execlist_port[0].count = 0;
>  		engine->execlist_port[1].count = 0;
> -		execlists_submit_ports(engine);
> +		if (!dev_priv->guc.execbuf_client)
> +			execlists_submit_ports(engine);

Not sure what you were intending to do here as this only resets the
submission count -- which is not used by guc dequeue. Some merit in the
making the code look similar, certainly adds the dbg message but I think
it is unrelated to the rest of the patch.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre