[Intel-gfx] [PATCH] drm/i915: Reject fence stride=0 on gen4+

[Daniel Vetter]

On Tue, Apr 09, 2013 at 05:46:45PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Our checks for an invalid fence stride forgot to guard against
> zero stride on gen4+. Fix it.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

This duplicates the tiny stride check a bit with the gen2/3 code. What
about


diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index c807eb9..b56185f 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -235,6 +235,9 @@ i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
 		}
 	}
 
+	if (stride < tile_width)
+		return false;
+
 	/* 965+ just needs multiples of tile width */
 	if (INTEL_INFO(dev)->gen >= 4) {
 		if (stride & (tile_width - 1))
@@ -243,9 +246,6 @@ i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
 	}
 
 	/* Pre-965 needs power of two tile widths */
-	if (stride < tile_width)
-		return false;
-
 	if (stride & (stride - 1))
 		return false;
 
instead?
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem_tiling.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
> index 139d17d..16ff6e7 100644
> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
> @@ -240,6 +240,8 @@ i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
>  
>  	/* 965+ just needs multiples of tile width */
>  	if (INTEL_INFO(dev)->gen >= 4) {
> +		if (stride < tile_width)
> +			return false;
>  		if (stride & (tile_width - 1))
>  			return false;
>  		return true;
> -- 
> 1.8.1.5
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch