[Intel-gfx] [PATCH 4/6] drm/i915: Calculate min_ddb_alloc for trans_wm

[Lisovskiy, Stanislav]

On Fri, Mar 05, 2021 at 05:36:08PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Let's make all the "do we have enough DDB for this WM level?"
> checks use min_ddb_alloc. To achieve that we need to populate
> this for the transition watermarks as well.
> 
> Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)

Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>

> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 36601e0a5073..38a6feced74f 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4986,13 +4986,13 @@ skl_allocate_plane_ddb(struct intel_atomic_state *state,
>  		struct skl_plane_wm *wm =
>  			&crtc_state->wm.skl.optimal.planes[plane_id];
>  
> -		if (wm->trans_wm.plane_res_b >= total[plane_id])
> +		if (wm->trans_wm.min_ddb_alloc > total[plane_id])
>  			memset(&wm->trans_wm, 0, sizeof(wm->trans_wm));
>  
>  		if (wm->sagv.wm0.min_ddb_alloc > total[plane_id])
>  			memset(&wm->sagv.wm0, 0, sizeof(wm->sagv.wm0));
>  
> -		if (wm->sagv.trans_wm.plane_res_b >= total[plane_id])
> +		if (wm->sagv.trans_wm.min_ddb_alloc > total[plane_id])
>  			memset(&wm->sagv.trans_wm, 0, sizeof(wm->sagv.trans_wm));
>  	}
>  
> @@ -5404,13 +5404,15 @@ static void skl_compute_transition_wm(struct drm_i915_private *dev_priv,
>  	} else {
>  		res_blocks = wm0_sel_res_b + trans_offset_b;
>  	}
> +	res_blocks++;
>  
>  	/*
>  	 * Just assume we can enable the transition watermark.  After
>  	 * computing the DDB we'll come back and disable it if that
>  	 * assumption turns out to be false.
>  	 */
> -	trans_wm->plane_res_b = res_blocks + 1;
> +	trans_wm->plane_res_b = res_blocks;
> +	trans_wm->min_ddb_alloc = max_t(u16, wm0->min_ddb_alloc, res_blocks + 1);
>  	trans_wm->plane_en = true;
>  }
>  
> -- 
> 2.26.2
>