[Intel-gfx] [PATCH v3 3/6] drm/i915: Clean up fbc vs. plane checks

[Chris Wilson]

Quoting Ville Syrjala (2018-02-21 17:31:01)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Let's record the information whether a plane can do fbc or not under
> struct inte_plane.
> 
> v2: Rebase due to i9xx_plane_id
>     Handle BDW/HSW correctly
> v3: Move inte_fbc_init() back since we depend on it happening
>     even with i915.disable_display, and populate
>     fbc->possible_framebuffer_bits directly from the
>     plane init code instead
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h     |  1 +
>  drivers/gpu/drm/i915/intel_fbc.c     | 26 ++---------------------
>  3 files changed, 44 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index d2a66704e6f5..c60d2215b377 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13238,6 +13238,32 @@ static const struct drm_plane_funcs intel_cursor_plane_funcs = {
>         .format_mod_supported = intel_cursor_plane_format_mod_supported,
>  };
>  
> +static bool i9xx_plane_has_fbc(struct drm_i915_private *dev_priv,
> +                              enum i9xx_plane_id i9xx_plane)
> +{
> +       if (!HAS_FBC(dev_priv))
> +               return false;

> -static inline bool fbc_on_pipe_a_only(struct drm_i915_private *dev_priv)
> -{
> -       return IS_HASWELL(dev_priv) || INTEL_GEN(dev_priv) >= 8;
> -}
> -
> -static inline bool fbc_on_plane_a_only(struct drm_i915_private *dev_priv)
> -{
> -       return INTEL_GEN(dev_priv) < 4;
> -}

> +
> +       if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
> +               return i9xx_plane == PLANE_A;

Where PLANE_A is tied to PIPE_A by construction. Is that worth a quick
comment?

> +       else if (IS_IVYBRIDGE(dev_priv))
> +               return i9xx_plane == PLANE_A || i9xx_plane == PLANE_B ||
> +                       i9xx_plane == PLANE_C;
> +       else if (INTEL_GEN(dev_priv) >= 4)
> +               return i9xx_plane == PLANE_A || i9xx_plane == PLANE_B;
> +       else
> +               return i9xx_plane == PLANE_A;

Ok, looks a bit more complete than before.

> +}
> +
> +static bool skl_plane_has_fbc(struct drm_i915_private *dev_priv,
> +                             enum pipe pipe, enum plane_id plane_id)
> +{
> +       if (!HAS_FBC(dev_priv))
> +               return false;
> +
> +       return pipe == PIPE_A && plane_id == PLANE_PRIMARY;
> +}
> +
>  static struct intel_plane *
>  intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
>  {
> @@ -13280,6 +13306,21 @@ intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
>                 primary->i9xx_plane = (enum i9xx_plane_id) pipe;
>         primary->id = PLANE_PRIMARY;
>         primary->frontbuffer_bit = INTEL_FRONTBUFFER(pipe, primary->id);
> +
> +       if (INTEL_GEN(dev_priv) >= 9)
> +               primary->has_fbc = skl_plane_has_fbc(dev_priv,
> +                                                    primary->pipe,
> +                                                    primary->id);
> +       else
> +               primary->has_fbc = i9xx_plane_has_fbc(dev_priv,
> +                                                     primary->i9xx_plane);
> +
> +       if (primary->has_fbc) {
> +               struct intel_fbc *fbc = &dev_priv->fbc;
> +
> +               fbc->possible_framebuffer_bits |= primary->frontbuffer_bit;
> +       }

So an equivalent init loop to

> -       for_each_pipe(dev_priv, pipe) {
> -               fbc->possible_framebuffer_bits |=
> -                       INTEL_FRONTBUFFER(pipe, PLANE_PRIMARY);
> -
> -               if (fbc_on_pipe_a_only(dev_priv))
> -                       break;
> -       }

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris