[Intel-gfx] [PATCH 07/15] drm/i915: Add BUILD_BUG_ON()s for DDI translation table sizes

[Ville Syrjälä]

On Thu, Dec 10, 2015 at 02:28:32PM +0100, Daniel Vetter wrote:
> On Tue, Dec 08, 2015 at 07:59:42PM +0200, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > The DDI translation tables are supposed to be of certain size,
> > so let's add some compile time asserts to enforce that..
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Not sure this is worth it really. Next patch seems more valuable. Not
> against it, but imo needs someone to really rave about it.

The hardware has a fixed number of registers for this stuff, so these
arrays had better match that 1:1.

> -Daniel
> 
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > index 5d0b03d6d388..838cbbe33517 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -351,6 +351,10 @@ intel_dig_port_supports_hdmi(const struct intel_digital_port *intel_dig_port)
> >  static const struct ddi_buf_trans *
> >  skl_get_buf_trans_dp(struct drm_i915_private *dev_priv, int *n_entries)
> >  {
> > +	BUILD_BUG_ON(ARRAY_SIZE(skl_y_ddi_translations_dp) != 9);
> > +	BUILD_BUG_ON(ARRAY_SIZE(skl_u_ddi_translations_dp) != 9);
> > +	BUILD_BUG_ON(ARRAY_SIZE(skl_ddi_translations_dp) != 9);
> > +
> >  	if (IS_SKL_ULX(dev_priv)) {
> >  		*n_entries = ARRAY_SIZE(skl_y_ddi_translations_dp);
> >  		return skl_y_ddi_translations_dp;
> > @@ -366,6 +370,10 @@ skl_get_buf_trans_dp(struct drm_i915_private *dev_priv, int *n_entries)
> >  static const struct ddi_buf_trans *
> >  skl_get_buf_trans_edp(struct drm_i915_private *dev_priv, int *n_entries)
> >  {
> > +	BUILD_BUG_ON(ARRAY_SIZE(skl_y_ddi_translations_edp) != 10);
> > +	BUILD_BUG_ON(ARRAY_SIZE(skl_u_ddi_translations_edp) != 10);
> > +	BUILD_BUG_ON(ARRAY_SIZE(skl_ddi_translations_edp) != 10);
> > +
> >  	if (dev_priv->edp_low_vswing) {
> >  		if (IS_SKL_ULX(dev_priv)) {
> >  			*n_entries = ARRAY_SIZE(skl_y_ddi_translations_edp);
> > @@ -436,6 +444,10 @@ static void intel_prepare_ddi_buffers(struct drm_i915_private *dev_priv,
> >  		    dev_priv->vbt.ddi_port_info[port].dp_boost_level)
> >  			iboost_bit = 1<<31;
> >  	} else if (IS_BROADWELL(dev_priv)) {
> > +		BUILD_BUG_ON(ARRAY_SIZE(bdw_ddi_translations_fdi) != 9);
> > +		BUILD_BUG_ON(ARRAY_SIZE(bdw_ddi_translations_dp) != 9);
> > +		BUILD_BUG_ON(ARRAY_SIZE(bdw_ddi_translations_edp) != 9);
> > +
> >  		ddi_translations_fdi = bdw_ddi_translations_fdi;
> >  		ddi_translations_dp = bdw_ddi_translations_dp;
> >  		ddi_translations_edp = bdw_ddi_translations_edp;
> > @@ -445,6 +457,9 @@ static void intel_prepare_ddi_buffers(struct drm_i915_private *dev_priv,
> >  		n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi);
> >  		hdmi_default_entry = 7;
> >  	} else if (IS_HASWELL(dev_priv)) {
> > +		BUILD_BUG_ON(ARRAY_SIZE(hsw_ddi_translations_fdi) != 9);
> > +		BUILD_BUG_ON(ARRAY_SIZE(hsw_ddi_translations_dp) != 9);
> > +
> >  		ddi_translations_fdi = hsw_ddi_translations_fdi;
> >  		ddi_translations_dp = hsw_ddi_translations_dp;
> >  		ddi_translations_edp = hsw_ddi_translations_dp;
> > -- 
> > 2.4.10
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Ville Syrjälä
Intel OTC