[Intel-gfx] [PATCH] drm/i915: Silence compiler for csr_load_work_fn()

[Michal Wajdeczko]

On Tue, 07 Nov 2017 15:53:34 +0100, Chris Wilson  
<chris at chris-wilson.co.uk> wrote:

> gcc-4.7 is not very smart and can not tell that "si" is guarded by size
> being 0. So it complains,
>
> drivers/gpu/drm/i915/intel_csr.c: In function ‘csr_load_work_fn’:
> drivers/gpu/drm/i915/intel_csr.c:204:3: warning: ‘si’ may be used  
> uninitialized in this function [-Wmaybe-uninitialized]
> drivers/gpu/drm/i915/intel_csr.c:190:30: note: ‘si’ was declared in
>
> Give in and mark si as NULL.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Imre Deak <imre.deak at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_csr.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_csr.c  
> b/drivers/gpu/drm/i915/intel_csr.c
> index 3e1f86d0c6cc..77d8b3d483ca 100644
> --- a/drivers/gpu/drm/i915/intel_csr.c
> +++ b/drivers/gpu/drm/i915/intel_csr.c
> @@ -198,6 +198,7 @@ intel_get_stepping_info(struct drm_i915_private  
> *dev_priv)
>  		si = bxt_stepping_info;
>  	} else {
>  		size = 0;
> +		si = NULL;
>  	}
> 	if (INTEL_REVID(dev_priv) < size)

Not only gcc was complaning here, smatch report was similar:

drivers/gpu/drm/i915/intel_csr.c:204
  intel_get_stepping_info() error: uninitialized symbol 'si'

and marking si as NULL silence that error too, so:

Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com>

But at the same time I'm wondering if is it ok that we silently
convert higher SKL/BXT revisions into wildcard ... but this is
another story.

Michal