Re: [PATCH 06/24] drm/i915: properly check for pipe count

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Thu, 26 Apr 2012 15:21:01 -0300
Eugeni Dodonov <eugeni.dodonov@intel.com> wrote:

> As suggested by Chris Wilson and Daniel Vetter, this chunk of code can be
> simplified with a more simple check.
> 
> CC: Daniel Vetter <daniel.vetter@ffwll.ch>
> CC: Chris Wilson <chris@chris-wilson.co.uk>
> Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c |   14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 8262ec6..27f384d 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -1981,16 +1981,10 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
>  		return 0;
>  	}
>  
> -	switch (intel_crtc->plane) {
> -	case 0:
> -	case 1:
> -		break;
> -	case 2:
> -		if (IS_IVYBRIDGE(dev))
> -			break;
> -		/* fall through otherwise */
> -	default:
> -		DRM_ERROR("no plane for crtc\n");
> +	if(intel_crtc->plane > dev_priv->num_pipe) {
> +		DRM_ERROR("no plane for crtc: plane %d, num_pipes %d\n",
> +				intel_crtc->plane,
> +				dev_priv->num_pipe);
>  		return -EINVAL;
>  	}
>  

plane is an enum and num_pipe is an int, so we could be more paranoid
here about signs and < 0.

But meh.  These are purely driver internal, so we don't have to
validate them too hard.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center