[Intel-gfx] [PATCH 08/12] drm/i915: Allow calling intel_adjust_tile_offset() multiple times

[Daniel Vetter]

On Wed, Aug 10, 2016 at 12:23:17PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Minimize the resulting X coordinate after intel_adjust_tile_offset() is
> done with it's offset adjustment. This allows calling
> intel_adjust_tile_offset() multiple times in case we need to adjust
> the offset several times.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Do we check anywhere that y doesn't eventually overflow? Anyway, this
looks good.

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/i915/intel_display.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index f4b45625703e..40c809593ae9 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2330,6 +2330,7 @@ static u32 intel_adjust_tile_offset(int *x, int *y,
>  				    u32 old_offset,
>  				    u32 new_offset)
>  {
> +	unsigned int pitch_pixels = pitch_tiles * tile_width;
>  	unsigned int tiles;
>  
>  	WARN_ON(old_offset & (tile_size - 1));
> @@ -2341,6 +2342,10 @@ static u32 intel_adjust_tile_offset(int *x, int *y,
>  	*y += tiles / pitch_tiles * tile_height;
>  	*x += tiles % pitch_tiles * tile_width;
>  
> +	/* minimize x in case it got needlessly big */
> +	*y += *x / pitch_pixels * tile_height;
> +	*x %= pitch_pixels;
> +
>  	return new_offset;
>  }
>  
> -- 
> 2.7.4
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch