[Intel-gfx] [PATCH 3/4] drm/i915: Bail if plane/crtc init fails

[Chris Wilson]

On Tue, Oct 25, 2016 at 06:58:02PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Due to the plane->index not getting readjusted in drm_plane_cleanup(),
> we can't continue initialization of some plane/crtc init fails.
> Well, we sort of could I suppose if we left all initialized planes on
> the list, but that would expose those planes to userspace as well.
> 
> But for crtcs the situation is even worse since we assume that
> pipe==crtc index occasionally, so we can't really deal with a partially
> initialize set of crtcs.
> 
> So seems safest to just abort the entire thing if anything goes wrong.
> All the failure paths here are kmalloc()s anyway, so it seems unlikely
> we'd get very far if these start failing.

smatch spotted ERR_PTR(0)

> @@ -15296,22 +15304,30 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
>  	}
>  
>  	primary = intel_primary_plane_create(dev, pipe);
> -	if (!primary)
> +	if (IS_ERR(primary)) {
> +		ret = PTR_ERR(primary);

Here...

>  		goto fail;
> +	}
>  
>  	for_each_sprite(dev_priv, pipe, sprite) {
> -		ret = intel_plane_init(dev, pipe, sprite);
> -		if (ret)
> -			DRM_DEBUG_KMS("pipe %c sprite %c init failed: %d\n",
> -				      pipe_name(pipe), sprite_name(pipe, sprite), ret);
> +		struct intel_plane *plane;
> +
> +		plane = intel_sprite_plane_create(dev, pipe, sprite);
> +		if (!plane) {
> +			ret = PTR_ERR(plane);

and here.

-- 
Chris Wilson, Intel Open Source Technology Centre