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

Zanoni, Paulo R paulo.r.zanoni at intel.com
Fri Sep 2 12:21:25 UTC 2016


Em Sex, 2016-09-02 às 17:16 +0530, Mahesh Kumar escreveu:
> Hi,
> 
> On Wednesday 31 August 2016 07:17 PM, Zanoni, Paulo R wrote:
> > 
> > Em Ter, 2016-08-30 às 19:32 +0000, Zanoni, Paulo R escreveu:
> > > 
> > > 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?
> This value 10 was driven by experiments in other OS with the help of
> SV 
> team.
> I'm trying to get more information regarding this from HW/SV team.
> we can update this value later if required, what is your thought on
> this?
> > 
> > I kept investigating and it seems that the current recommendation
> > is
> > still that transition watermarks stay disabled for SKL and KBL.
> 
> My earlier impression from Bspec was transition WM's should be
> disabled 
> in SKL A/B stepping only. But from the latest discussion with HW
> team,
> it seems transition WM must be disabled for all SKL stepping.
> SV team recommendation is, It should be enabled with IPC for BXT/APL 
> systems, So will update the patch with IS_BXT() check.

BSpec says transition watermarks should be disabled for GEN9:ALL.

Arthur, can you please comment on this?

> 
> thanks,
> 
> Regards,
> -Mahesh
> > 
> > 
> > > 
> > > 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;
> > > >   }
> > > _______________________________________________
> > > Intel-gfx mailing list
> > > Intel-gfx at lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 


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