[Intel-gfx] [PATCH] FOR_UPSTREAM [VPG]: drm/i915/skl+: Implement Transition WM

[Zanoni, Paulo R]

Hi

Em Seg, 2016-08-29 às 18:05 +0530, Kumar, Mahesh escreveu:
> This patch enables Transition WM for SKL+ platforms.
> 
> Transition WM are used if IPC is enabled, to decide, number of blocks
> to be fetched before reducing the priority of display to fetch from
> memory.
> 
> Signed-off-by: Kumar, Mahesh <mahesh1.kumar at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 57
> ++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 53 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c
> b/drivers/gpu/drm/i915/intel_pm.c
> index 9f69050..f4f387f 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -2861,6 +2861,8 @@ bool ilk_disable_lp_wm(struct drm_device *dev)
>  #define SKL_DDB_SIZE		896	/* in blocks */
>  #define BXT_DDB_SIZE		512
>  #define SKL_SAGV_BLOCK_TIME	30 /* µs */
> +#define SKL_TRANS_WM_AMOUNT	10
> +#define SKL_TRANS_WM_MIN	14

As far as I understood (and maybe I'm wrong), SKL_TRANS_WM_AMOUNT is a
tunable value, so it depends on a lot of variable factors. Why does
this patch use 10 instead of every other possible value?

Thanks,
Paulo


>  
>  /*
>   * Return the index of a plane in the SKL DDB and wm result
> arrays.  Primary
> @@ -3579,6 +3581,41 @@ static uint32_t
> skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cst
>  	return pixel_rate;
>  }
>  
> +static void skl_compute_plane_trans_wm(const struct drm_i915_private
> *dev_priv,
> +					struct skl_pipe_wm *pipe_wm,
> +					struct intel_plane_state
> *intel_pstate,
> +					uint32_t y_tile_min,
> +					bool y_tile)
> +{
> +	struct drm_plane_state *pstate = &intel_pstate->base;
> +	int id = skl_wm_plane_id(to_intel_plane(pstate->plane));
> +	uint16_t *out_blocks = &pipe_wm->trans_wm.plane_res_b[id];
> +	uint8_t *out_lines = &pipe_wm->trans_wm.plane_res_l[id];
> +	uint16_t res_blocks = pipe_wm->wm[0].plane_res_b[id];
> +	uint32_t trans_min = 0, trans_offset_blocks;
> +	uint16_t trans_y_tile_min = 0;
> +	uint16_t trans_res_blocks;
> +
> +
> +	if (IS_GEN9(dev_priv))
> +		trans_min = SKL_TRANS_WM_MIN;
> +
> +	trans_offset_blocks = trans_min + SKL_TRANS_WM_AMOUNT;
> +
> +	if (y_tile) {
> +		trans_y_tile_min = 2 * y_tile_min;
> +		trans_res_blocks = max(trans_y_tile_min, res_blocks)
> +
> +			trans_offset_blocks;
> +	} else {
> +		trans_res_blocks = res_blocks + trans_offset_blocks;
> +		/* WA BUG:1938466 add one block for non y-tile
> planes */
> +		trans_res_blocks += 1;
> +	}
> +
> +	*out_blocks = trans_res_blocks;
> +	*out_lines = 0;
> +}
> +
>  static int skl_compute_plane_wm(const struct drm_i915_private
> *dev_priv,
>  				struct intel_crtc_state *cstate,
>  				struct intel_plane_state
> *intel_pstate,
> @@ -3600,6 +3637,8 @@ static int skl_compute_plane_wm(const struct
> drm_i915_private *dev_priv,
>  	struct skl_wm_level *result = &pipe_wm->wm[level];
>  	uint16_t *out_blocks = &result->plane_res_b[id];
>  	uint8_t *out_lines = &result->plane_res_l[id];
> +	uint32_t y_tile_minimum = 0;
> +	bool y_tile = false;
>  
>  	if (latency == 0 || !cstate->base.active || !intel_pstate-
> >base.visible)
>  		return 0;
> @@ -3627,7 +3666,6 @@ static int skl_compute_plane_wm(const struct
> drm_i915_private *dev_priv,
>  	if (fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
>  	    fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED) {
>  		uint32_t min_scanlines = 4;
> -		uint32_t y_tile_minimum;
>  		if (intel_rotation_90_or_270(pstate->rotation)) {
>  			int cpp = (fb->pixel_format ==
> DRM_FORMAT_NV12) ?
>  				drm_format_plane_cpp(fb-
> >pixel_format, 1) :
> @@ -3646,6 +3684,7 @@ static int skl_compute_plane_wm(const struct
> drm_i915_private *dev_priv,
>  		}
>  		y_tile_minimum = plane_blocks_per_line *
> min_scanlines;
>  		selected_result = max(method2, y_tile_minimum);
> +		y_tile = true;
>  	} else {
>  		linetime_us = DIV_ROUND_UP(width * 1000,
>  				skl_pipe_pixel_rate(cstate));
> @@ -3669,6 +3708,9 @@ static int skl_compute_plane_wm(const struct
> drm_i915_private *dev_priv,
>  	*out_blocks = res_blocks;
>  	*out_lines = res_lines;
>  
> +	if (level == 0)
> +		skl_compute_plane_trans_wm(dev_priv, pipe_wm,
> intel_pstate,
> +						y_tile_minimum,
> y_tile);
>  	return 0;
>  }
>  
> @@ -3738,11 +3780,13 @@ skl_compute_linetime_wm(struct
> intel_crtc_state *cstate)
>  }
>  
>  static void skl_compute_transition_wm(struct intel_crtc_state
> *cstate,
> -				      struct skl_wm_level *trans_wm
> /* out */)
> +				      struct skl_wm_level *trans_wm,
> +				      struct skl_ddb_allocation
> *ddb)
>  {
>  	struct drm_crtc *crtc = cstate->base.crtc;
>  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>  	struct intel_plane *intel_plane;
> +	enum pipe pipe = to_intel_crtc(crtc)->pipe;
>  
>  	if (!cstate->base.active)
>  		return;
> @@ -3750,8 +3794,13 @@ static void skl_compute_transition_wm(struct
> intel_crtc_state *cstate,
>  	/* Until we know more, just disable transition WMs */
>  	for_each_intel_plane_on_crtc(crtc->dev, intel_crtc,
> intel_plane) {
>  		int i = skl_wm_plane_id(intel_plane);
> +		uint16_t plane_ddb = skl_ddb_entry_size(&ddb-
> >plane[pipe][i]);
> +		uint16_t trans_res_blocks = trans_wm-
> >plane_res_b[i];
>  
> -		trans_wm->plane_en[i] = false;
> +		if ((plane_ddb == 0) || (trans_res_blocks >
> plane_ddb))
> +			trans_wm->plane_en[i] = false;
> +		else
> +			trans_wm->plane_en[i] = true;
>  	}
>  }
>  
> @@ -3782,7 +3831,7 @@ static int skl_build_pipe_wm(struct
> intel_crtc_state *cstate,
>  
>  	pipe_wm->linetime = skl_compute_linetime_wm(cstate);
>  
> -	skl_compute_transition_wm(cstate, &pipe_wm->trans_wm);
> +	skl_compute_transition_wm(cstate, &pipe_wm->trans_wm, ddb);
>  
>  	return 0;
>  }