[Intel-gfx] [PATCH 05/11] drm/i915: Check framebuffer stride more thoroughly

[Jesse Barnes]

On Wed, 31 Oct 2012 17:50:18 +0200
ville.syrjala at linux.intel.com wrote:

> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Make sure the the framebuffer stride is smaller than 32k. That
> seems to be the limit on recent hardware. Not quite sure if
> <=Gen4 has smaller limits.
> 
> Also when using a tiled memory make sure the object stride matches
> the framebuffer stride.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
> 
> I had an earlier version a long time ago that tried to use smaller stride limits
> on <=Gen4, but as there isn't clear information what those limits are, I decided
> to just check for the 32K limit everywhere. It's definitely an upper bound for
> the older hardware as well.
> 
>  drivers/gpu/drm/i915/intel_display.c |    8 ++++++++
>  1 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b42637b..f431f2a 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -8235,6 +8235,14 @@ int intel_framebuffer_init(struct drm_device *dev,
>  	if (mode_cmd->pitches[0] & 63)
>  		return -EINVAL;
>  
> +	/* FIXME <= Gen4 stride limits are bit unclear */
> +	if (mode_cmd->pitches[0] > 32768)
> +		return -EINVAL;
> +
> +	if (obj->tiling_mode != I915_TILING_NONE &&
> +	    mode_cmd->pitches[0] != obj->stride)
> +		return -EINVAL;
> +
>  	/* Reject formats not supported by any plane early. */
>  	switch (mode_cmd->pixel_format) {
>  	case DRM_FORMAT_C8:

The bspec archive should have the pre-gen4 info, but this is a good
start.

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

-- 
Jesse Barnes, Intel Open Source Technology Center