[Intel-gfx] [PATCH 21/59] drm/i915: Add explicit request management to i915_gem_init_hw()

[Tomas Elf]

On 19/03/2015 12:30, John.C.Harrison at Intel.com wrote:
> From: John Harrison <John.C.Harrison at Intel.com>
>
> Now that a single per ring loop is being done for all the different
> intialisation steps in i915_gem_init_hw(), it is possible to add proper request
> management as well. The last remaining issue is that the context enable call
> eventually ends up within *_render_state_init() and this does it's own private

Nitpick: "it's own private" : "it's" -> "its"

> _i915_add_request() call.
>
> This patch adds explicit request creation and submission to the top level loop
> and removes the add_request() from deep within the sub-functions. Note that the
> old add_request() call was being passed a batch object. This is now explicitly
> written to the request object instead. A warning has also been added to
> i915_add_request() to ensure that there is never an attempt to add two batch
> objects to a single request - e.g. because render_state_init() was called during
> execbuffer processing.

"A warning has also been added" : No it hasn't. After discussion with 
John it turns out that this part of the commit message is old and should 
be removed.

>
> v2: Updated for removal of batch_obj from add_request call in previous patch
> (which is new to series).
>
> For: VIZ-5115
> Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
> ---
>   drivers/gpu/drm/i915/i915_drv.h              |    3 ++-
>   drivers/gpu/drm/i915/i915_gem.c              |   12 ++++++++++++
>   drivers/gpu/drm/i915/i915_gem_render_state.c |    2 --
>   drivers/gpu/drm/i915/intel_lrc.c             |    5 -----
>   4 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index cc957d5..aa0695b 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2082,7 +2082,8 @@ struct drm_i915_gem_request {
>   	struct intel_context *ctx;
>   	struct intel_ringbuffer *ringbuf;
>
> -	/** Batch buffer related to this request if any */
> +	/** Batch buffer related to this request if any (used for
> +	    error state dump only) */
>   	struct drm_i915_gem_object *batch_obj;
>
>   	/** Time at which this request was emitted, in jiffies. */
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 29568c4..4452618 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -4900,8 +4900,16 @@ i915_gem_init_hw(struct drm_device *dev)
>
>   	/* Now it is safe to go back round and do everything else: */
>   	for_each_ring(ring, dev_priv, i) {
> +		struct drm_i915_gem_request *req;
> +
>   		WARN_ON(!ring->default_context);
>
> +		ret = i915_gem_request_alloc(ring, ring->default_context, &req);
> +		if (ret) {
> +			i915_gem_cleanup_ringbuffer(dev);
> +			goto out;
> +		}
> +
>   		if (ring->id == RCS) {
>   			for (i = 0; i < NUM_L3_SLICES(dev); i++)
>   				i915_gem_l3_remap(ring, i);
> @@ -4910,6 +4918,7 @@ i915_gem_init_hw(struct drm_device *dev)
>   		ret = i915_ppgtt_init_ring(ring);
>   		if (ret && ret != -EIO) {
>   			DRM_ERROR("PPGTT enable ring #%d failed %d\n", i, ret);
> +			i915_gem_request_cancel(req);
>   			i915_gem_cleanup_ringbuffer(dev);
>   			goto out;
>   		}
> @@ -4917,9 +4926,12 @@ i915_gem_init_hw(struct drm_device *dev)
>   		ret = i915_gem_context_enable(ring);
>   		if (ret && ret != -EIO) {
>   			DRM_ERROR("Context enable ring #%d failed %d\n", i, ret);
> +			i915_gem_request_cancel(req);
>   			i915_gem_cleanup_ringbuffer(dev);
>   			goto out;
>   		}
> +
> +		i915_add_request_no_flush(ring);
>   	}
>
>   out:
> diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c
> index a32a4b9..a07b4ee 100644
> --- a/drivers/gpu/drm/i915/i915_gem_render_state.c
> +++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
> @@ -173,8 +173,6 @@ int i915_gem_render_state_init(struct intel_engine_cs *ring)
>
>   	i915_vma_move_to_active(i915_gem_obj_to_ggtt(so.obj), ring);
>
> -	__i915_add_request(ring, NULL, NULL, true);
> -	/* __i915_add_request moves object to inactive if it fails */
>   out:
>   	i915_gem_render_state_fini(&so);
>   	return ret;
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index f24ab0c..b430e51 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -1330,8 +1330,6 @@ static int intel_lr_context_render_state_init(struct intel_engine_cs *ring,
>   {
>   	struct intel_ringbuffer *ringbuf = ctx->engine[ring->id].ringbuf;
>   	struct render_state so;
> -	struct drm_i915_file_private *file_priv = ctx->file_priv;
> -	struct drm_file *file = file_priv ? file_priv->file : NULL;
>   	int ret;
>
>   	ret = i915_gem_render_state_prepare(ring, &so);
> @@ -1350,9 +1348,6 @@ static int intel_lr_context_render_state_init(struct intel_engine_cs *ring,
>
>   	i915_vma_move_to_active(i915_gem_obj_to_ggtt(so.obj), ring);
>
> -	__i915_add_request(ring, file, NULL, true);
> -	/* intel_logical_ring_add_request moves object to inactive if it
> -	 * fails */
>   out:
>   	i915_gem_render_state_fini(&so);
>   	return ret;
>