[Intel-gfx] [PATCH 4/4] drm/i915: Don't allocate extra ddb during async flip for DG2
Lisovskiy, Stanislav
stanislav.lisovskiy at intel.com
Mon Jan 24 09:29:27 UTC 2022
On Mon, Jan 24, 2022 at 11:16:36AM +0200, Ville Syrjälä wrote:
> On Mon, Jan 24, 2022 at 11:06:53AM +0200, Stanislav Lisovskiy wrote:
> > In terms of async flip optimization we don't to allocate
> > extra ddb space, so lets skip it.
> >
> > v2: - Extracted min ddb async flip check to separate function
> > (Ville Syrjälä)
> > - Used this function to prevent false positive WARN
> > to be triggered(Ville Syrjälä)
> >
> > v3: - Renamed dg2_need_min_ddb to need_min_ddb thus making
> > it more universal.
> > - Also used DISPLAY_VER instead of IS_DG2(Ville Syrjälä)
> > - Use rate = 0 instead of just setting extra = 0, thus
> > letting other planes to use extra ddb and avoiding WARN
> > (Ville Syrjälä)
> >
> > v4: - Renamed needs_min_ddb as s/needs/use/ to match
> > the wm0 counterpart(Ville Syrjälä)
> > - Added plane->async_flip check to use_min_ddb(now
> > passing plane as a parameter to do that)(Ville Syrjälä)
> > - Account for use_min_ddb also when calculating total data rate
> > (Ville Syrjälä)
> >
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > ---
> > .../gpu/drm/i915/display/intel_atomic_plane.c | 2 +-
> > .../gpu/drm/i915/display/intel_atomic_plane.h | 3 +-
> > drivers/gpu/drm/i915/intel_pm.c | 53 ++++++++++++++-----
> > 3 files changed, 44 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > index b20cf2c16691..9d79ab987b2e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > @@ -374,7 +374,7 @@ int intel_plane_atomic_check_with_state(const struct intel_crtc_state *old_crtc_
> > old_plane_state, new_plane_state);
> > }
> >
> > -static struct intel_plane *
> > +struct intel_plane *
> > intel_crtc_get_plane(struct intel_crtc *crtc, enum plane_id plane_id)
> > {
> > struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.h b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
> > index ead789709477..aaddcc636f98 100644
> > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.h
> > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
> > @@ -23,7 +23,8 @@ unsigned int intel_adjusted_rate(const struct drm_rect *src,
> > unsigned int rate);
> > unsigned int intel_plane_pixel_rate(const struct intel_crtc_state *crtc_state,
> > const struct intel_plane_state *plane_state);
> > -
> > +struct intel_plane *intel_crtc_get_plane(struct intel_crtc *crtc,
> > + enum plane_id plane_id);
> > unsigned int intel_plane_data_rate(const struct intel_crtc_state *crtc_state,
> > const struct intel_plane_state *plane_state);
> > void intel_plane_copy_uapi_to_hw_state(struct intel_plane_state *plane_state,
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 8269f1e9c784..fbe6a45801bc 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -4988,6 +4988,25 @@ skl_get_total_relative_data_rate(struct intel_atomic_state *state,
> > return total_data_rate;
> > }
> >
> > +static bool use_min_ddb(struct intel_crtc_state *crtc_state,
> > + struct intel_plane *plane)
> > +{
> > + struct drm_i915_private *i915 = to_i915(plane->base.dev);
> > +
> > + return DISPLAY_VER(i915) >= 13 && crtc_state->uapi.async_flip &&
> > + plane->async_flip;
> > +}
> > +
> > +static bool use_minimal_wm0_only(const struct intel_crtc_state *crtc_state,
> > + struct intel_plane *plane)
>
> Please put this function into the right spot to begin with.
> Avoids polluting this patch with unrelated code movement.
It happened this way, because initially use_minimal_wm0_only which
is needed only by skl_compute_plane_wm was much lower, however as
you recommended to group it with use_min_ddb, so had to move it higher,
because use_min_ddb is required way higher in the file.
However I will then change the patch where it was introduced, so that
its already there.
>
> > +{
> > + struct drm_i915_private *i915 = to_i915(plane->base.dev);
> > +
> > + return DISPLAY_VER(i915) >= 13 &&
> > + crtc_state->uapi.async_flip &&
> > + plane->async_flip;
>
> Line wrapping is different between the two functions despite the
> identical contents, which looks a bit weird.
>
> > +}
> > +
> > static u64
> > icl_get_total_relative_data_rate(struct intel_atomic_state *state,
> > struct intel_crtc *crtc)
> > @@ -5033,8 +5052,15 @@ icl_get_total_relative_data_rate(struct intel_atomic_state *state,
> > }
> > }
> >
> > - for_each_plane_id_on_crtc(crtc, plane_id)
> > - total_data_rate += crtc_state->plane_data_rate[plane_id];
> > + for_each_new_intel_plane_in_state(state, plane, plane_state, i) {
>
> for_each_intel_plane_on_crtc() otherwise we miss all
> the planes not in the state.
Right, we recalculate those which changed first, then get total data rate.
For some reason I was looking at first cycle so just took same macro.
>
> > + /*
> > + * We calculate extra ddb based on ratio plane rate/total data rate
> > + * in case, in some cases we should not allocate extra ddb for the plane,
> > + * so do not count its data rate, if this is the case.
> > + */
> > + if (!use_min_ddb(crtc_state, plane))
> > + total_data_rate += crtc_state->plane_data_rate[plane->id];
> > + }
> >
> > return total_data_rate;
> > }
> > @@ -5199,6 +5225,8 @@ skl_allocate_plane_ddb(struct intel_atomic_state *state,
> > for_each_plane_id_on_crtc(crtc, plane_id) {
>
> for_each_intel_plane_on_crtc()...
>
> > const struct skl_plane_wm *wm =
> > &crtc_state->wm.skl.optimal.planes[plane_id];
> > + struct intel_plane *plane =
> > + intel_crtc_get_plane(crtc, plane_id);
>
> ... avoids needing that function.
>
> > u64 rate;
> > u16 extra;
> >
> > @@ -5213,9 +5241,14 @@ skl_allocate_plane_ddb(struct intel_atomic_state *state,
> > break;
> >
> > rate = crtc_state->plane_data_rate[plane_id];
> > +
> > + if (use_min_ddb(crtc_state, plane))
> > + rate = 0;
>
> else
> rate = crtc_state->plane_data_rate[plane_id];
>
> is how I'd write that probably.
>
> > +
> > extra = min_t(u16, alloc_size,
> > DIV64_U64_ROUND_UP(alloc_size * rate,
> > total_data_rate));
> > +
> > total[plane_id] = wm->wm[level].min_ddb_alloc + extra;
> > alloc_size -= extra;
> > total_data_rate -= rate;
> > @@ -5224,13 +5257,19 @@ skl_allocate_plane_ddb(struct intel_atomic_state *state,
> > break;
> >
> > rate = crtc_state->uv_plane_data_rate[plane_id];
> > +
> > + if (use_min_ddb(crtc_state, plane))
> > + rate = 0;
> > +
> > extra = min_t(u16, alloc_size,
> > DIV64_U64_ROUND_UP(alloc_size * rate,
> > total_data_rate));
> > +
> > uv_total[plane_id] = wm->uv_wm[level].min_ddb_alloc + extra;
> > alloc_size -= extra;
> > total_data_rate -= rate;
> > }
> > +
> > drm_WARN_ON(&dev_priv->drm, alloc_size != 0 || total_data_rate != 0);
> >
> > /* Set the actual DDB start/end points for each plane */
> > @@ -5497,16 +5536,6 @@ static int skl_wm_max_lines(struct drm_i915_private *dev_priv)
> > return 31;
> > }
> >
> > -static bool use_minimal_wm0_only(const struct intel_crtc_state *crtc_state,
> > - struct intel_plane *plane)
> > -{
> > - struct drm_i915_private *i915 = to_i915(plane->base.dev);
> > -
> > - return DISPLAY_VER(i915) >= 13 &&
> > - crtc_state->uapi.async_flip &&
> > - plane->async_flip;
> > -}
> > -
> > static void skl_compute_plane_wm(const struct intel_crtc_state *crtc_state,
> > struct intel_plane *plane,
> > int level,
> > --
> > 2.24.1.485.gad05a3d8e5
>
> --
> Ville Syrjälä
> Intel
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