[Intel-gfx] [PATCH 2/6] drm/i915: Treat kernel context as initialised

[Chris Wilson]

On Wed, May 25, 2016 at 12:48:49PM +0100, Chris Wilson wrote:
> The kernel context exists simply as a placeholder and should never be
> executed with a render context. It does not need the golden render
> state, as that will always be applied to a user context. By skipping the
> initialisation we can avoid issues in attempting to program the golden
> render context when trying to make the hardware idle.
> 
> Testcase: igt/drm_module_reload_basic #byt
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95634
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem_context.c | 45 +++++++++++++++++++++++----------
>  1 file changed, 32 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index a3b11aac23a4..3e3acd054f05 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -413,7 +413,8 @@ int i915_gem_context_init(struct drm_device *dev)
>  		return PTR_ERR(ctx);
>  	}
>  
> -	if (!i915.enable_execlists && ctx->engine[RCS].state) {
> +	if (!i915.enable_execlists) {
> +		struct intel_engine_cs *engine;
>  		int ret;
>  
>  		/* We may need to do things with the shrinker which
> @@ -423,13 +424,28 @@ int i915_gem_context_init(struct drm_device *dev)
>  		 * be available. To avoid this we always pin the default
>  		 * context.
>  		 */
> -		ret = i915_gem_obj_ggtt_pin(ctx->engine[RCS].state,
> -					    get_context_alignment(dev_priv), 0);
> -		if (ret) {
> -			DRM_ERROR("Failed to pinned default global context (error %d)\n",
> -				  ret);
> -			i915_gem_context_unreference(ctx);
> -			return ret;
> +		for_each_engine(engine, dev_priv) {

for_each_engine! Too early, we haven't yet initialised the engines.
The problem of trying to make it look neat.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre