Re: [PATCH 05/16] drm/i915: Move some computations out from hsw_compute_wm_parameters()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Oct 10, 2013 at 07:34:38PM -0300, Paulo Zanoni wrote:
> 2013/10/9  <ville.syrjala@linux.intel.com>:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > Move the watermark max computations into haswell_update_wm(). This
> > allows keeping the 1/2 vs. 5/6 split code in one place, and avoid having
> > to pass around so many things. We also save a bit of stack space by only
> > requiring one copy of struct hsw_wm_maximums.
> >
> > Also move the intel_wm_config out from hsw_compute_wm_parameters() and
> > pass it it. We'll have some need for it in haswell_update_wm() later.
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_pm.c | 33 ++++++++++++++-------------------
> >  1 file changed, 14 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index b09715f..0fe6c36 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -2586,13 +2586,11 @@ static void intel_setup_wm_latency(struct drm_device *dev)
> >
> >  static void hsw_compute_wm_parameters(struct drm_crtc *crtc,
> >                                       struct hsw_pipe_wm_parameters *p,
> > -                                     struct hsw_wm_maximums *lp_max_1_2,
> > -                                     struct hsw_wm_maximums *lp_max_5_6)
> > +                                     struct intel_wm_config *config)
> >  {
> >         struct drm_device *dev = crtc->dev;
> >         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> >         enum pipe pipe = intel_crtc->pipe;
> > -       struct intel_wm_config config = {};
> >         struct drm_plane *plane;
> >
> >         p->active = intel_crtc_active(crtc);
> > @@ -2609,7 +2607,7 @@ static void hsw_compute_wm_parameters(struct drm_crtc *crtc,
> >         }
> >
> >         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
> > -               config.num_pipes_active += intel_crtc_active(crtc);
> > +               config->num_pipes_active += intel_crtc_active(crtc);
> >
> >         list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> >                 struct intel_plane *intel_plane = to_intel_plane(plane);
> > @@ -2617,17 +2615,9 @@ static void hsw_compute_wm_parameters(struct drm_crtc *crtc,
> >                 if (intel_plane->pipe == pipe)
> >                         p->spr = intel_plane->wm;
> >
> > -               config.sprites_enabled |= intel_plane->wm.enabled;
> > -               config.sprites_scaled |= intel_plane->wm.scaled;
> > +               config->sprites_enabled |= intel_plane->wm.enabled;
> > +               config->sprites_scaled |= intel_plane->wm.scaled;
> >         }
> > -
> > -       ilk_wm_max(dev, 1, &config, INTEL_DDB_PART_1_2, lp_max_1_2);
> > -
> > -       /* 5/6 split only in single pipe config on IVB+ */
> > -       if (INTEL_INFO(dev)->gen >= 7 && config.num_pipes_active <= 1)
> > -               ilk_wm_max(dev, 1, &config, INTEL_DDB_PART_5_6, lp_max_5_6);
> > -       else
> > -               *lp_max_5_6 = *lp_max_1_2;
> >  }
> >
> >  /* Compute new watermarks for the pipe */
> > @@ -2889,14 +2879,15 @@ static void haswell_update_wm(struct drm_crtc *crtc)
> >         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> >         struct drm_device *dev = crtc->dev;
> >         struct drm_i915_private *dev_priv = dev->dev_private;
> > -       struct hsw_wm_maximums lp_max_1_2, lp_max_5_6;
> > +       struct hsw_wm_maximums max;
> >         struct hsw_pipe_wm_parameters params = {};
> >         struct hsw_wm_values results = {};
> >         enum intel_ddb_partitioning partitioning;
> >         struct intel_pipe_wm pipe_wm = {};
> >         struct intel_pipe_wm lp_wm_1_2 = {}, lp_wm_5_6 = {}, *best_lp_wm;
> > +       struct intel_wm_config config = {};
> >
> > -       hsw_compute_wm_parameters(crtc, &params, &lp_max_1_2, &lp_max_5_6);
> > +       hsw_compute_wm_parameters(crtc, &params, &config);
> >
> >         intel_compute_pipe_wm(crtc, &params, &pipe_wm);
> >
> > @@ -2905,10 +2896,14 @@ static void haswell_update_wm(struct drm_crtc *crtc)
> >
> >         intel_crtc->wm.active = pipe_wm;
> >
> > -       ilk_wm_merge(dev, &lp_max_1_2, &lp_wm_1_2);
> > -       ilk_wm_merge(dev, &lp_max_5_6, &lp_wm_5_6);
> > +       ilk_wm_max(dev, 1, &config, INTEL_DDB_PART_1_2, &max);
> > +       ilk_wm_merge(dev, &max, &lp_wm_1_2);
> > +
> > +       /* 5/6 split only in single pipe config on IVB+ */
> > +       if (INTEL_INFO(dev)->gen >= 7 && config.num_pipes_active <= 1) {
> 
> No need to calculate 5_6 on zero pipes, I guess.
> 
> 
> > +               ilk_wm_max(dev, 1, &config, INTEL_DDB_PART_5_6, &max);
> > +               ilk_wm_merge(dev, &max, &lp_wm_5_6);
> 
> Oh, so now you've moved ilk_wm_merge to the "if" statement, as I
> requested on the review to a previous patch :)
> 
> >
> > -       if (lp_max_1_2.pri != lp_max_5_6.pri) {
> 
> By removing this check, you're now also calculating 5_6 watermarks for
> the case where we just have 1 pipe but the sprites are disabled.

Hmm, right. I guess we should just add a more explicit
config.sprites_enabled check here to avoid that overhead.

> 
> 
> >                 best_lp_wm = hsw_find_best_result(dev, &lp_wm_1_2, &lp_wm_5_6);
> >         } else {
> >                 best_lp_wm = &lp_wm_1_2;
> > --
> > 1.8.1.5
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> 
> 
> -- 
> Paulo Zanoni

-- 
Ville Syrjälä
Intel OTC