[Intel-gfx] [PATCH 5/9] drm/i915: Make ring buffer size configurable

[Chris Wilson]

On Tue, May 17, 2016 at 04:19:05AM -0400, Zhi Wang wrote:
> This patch introduces an option for configuring ring buffer size during
> context creation. If no ring buffer size is specified, the default size
> (4 * PAGE_SIZE) will be used.
> 
> Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h  | 1 +
>  drivers/gpu/drm/i915/intel_lrc.c | 8 ++++++--
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index ea04352..cc83f2d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -883,6 +883,7 @@ struct intel_context {
>  		uint32_t *lrc_reg_state;
>  		bool initialised;
>  	} engine[I915_NUM_ENGINES];
> +	u32 ring_buffer_size;
>  
>  	struct list_head link;
>  };
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index db10c96..d52c806 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -2495,7 +2495,7 @@ static int execlists_context_deferred_alloc(struct intel_context *ctx,
>  					    struct intel_engine_cs *engine)
>  {
>  	struct drm_i915_gem_object *ctx_obj;
> -	uint32_t context_size;
> +	uint32_t context_size, ring_buffer_size;
>  	struct intel_ringbuffer *ringbuf;
>  	int ret;
>  
> @@ -2513,7 +2513,11 @@ static int execlists_context_deferred_alloc(struct intel_context *ctx,
>  		return PTR_ERR(ctx_obj);
>  	}
>  
> -	ringbuf = intel_engine_create_ringbuffer(engine, 4 * PAGE_SIZE);
> +	ring_buffer_size = ctx->ring_buffer_size;
> +	if (!ring_buffer_size)
> +		ring_buffer_size = 4 * PAGE_SIZE;

Just don't let it be zero (during construction).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre