Re: [PATCH 1/2] drm/i915: Use anonymous union/struct to save space taken by latency values

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Sep 05, 2014 at 01:53:11PM +0100, Damien Lespiau wrote:
> Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>

I think I'll punt on reviewing this for now. I need to go through
the other skl wm stuff first, and then I probaly need to stare at the
result a bit before I can think about unification.

> ---
>  drivers/gpu/drm/i915/i915_drv.h | 38 +++++++++++++++++++++-----------------
>  1 file changed, 21 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 0baf7f3..8471d12 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1730,23 +1730,27 @@ struct drm_i915_private {
>  	struct vlv_s0ix_state vlv_s0ix_state;
>  
>  	struct {
> -		/*
> -		 * Raw watermark latency values:
> -		 * in 0.1us units for WM0,
> -		 * in 0.5us units for WM1+.
> -		 */
> -		/* primary */
> -		uint16_t pri_latency[5];
> -		/* sprite */
> -		uint16_t spr_latency[5];
> -		/* cursor */
> -		uint16_t cur_latency[5];
> -		/*
> -		 * Raw watermark memory latency values
> -		 * for SKL for all 8 levels
> -		 * in 1us units.
> -		 */
> -		uint16_t skl_latency[8];
> +		union {
> +			/*
> +			 * Raw watermark latency values:
> +			 * in 0.1us units for WM0,
> +			 * in 0.5us units for WM1+.
> +			 */
> +			struct {
> +				/* primary */
> +				uint16_t pri_latency[5];
> +				/* sprite */
> +				uint16_t spr_latency[5];
> +				/* cursor */
> +				uint16_t cur_latency[5];
> +			};
> +
> +			/*
> +			 * Raw watermark memory latency values for SKL for all
> +			 * 8 levels. In 1us units.
> +			 */
> +			uint16_t skl_latency[8];
> +		};
>  
>  		/*
>  		 * The skl_wm_values structure is a bit too big for stack
> -- 
> 1.8.3.1

-- 
Ville Syrjälä
Intel OTC