On Mon, 2024-04-08 at 11:32 +0300, Lisovskiy, Stanislav wrote:
> On Fri, Apr 05, 2024 at 02:35:29PM +0300, Vinod Govindapillai wrote:
> > From: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> >
> > We need that in order to force disable SAGV in next patch.
> > Also it is beneficial to separate that code, as in majority cases,
> > when SAGV is enabled, we don't even need those calculations.
> > Also we probably need to determine max PSF GV point as well, however
> > currently we don't do that when we disable SAGV, which might be
> > actually causing some issues in that case.
> >
> > v2: - Introduce helper adl_qgv_bw(counterpart to adl_psf_bw)
> > (Ville Syrjälä)
> > - Don't restrict psf gv points for SAGV disable case
> > (Ville Syrjälä)
> > v3: - Update icl_max_bw_qgv_point_mask to return max qgv point
> > mask (Vinod)
> > v4: - Minor changes in icl_find_qgv_points (Vinod)
> >
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> > Signed-off-by: Vinod Govindapillai <vinod.govindapillai@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/intel_bw.c | 80 +++++++++++++++----------
> > 1 file changed, 50 insertions(+), 30 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
> > index 77886cc21211..c00094e5f11c 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bw.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> > @@ -661,6 +661,22 @@ static unsigned int adl_psf_bw(struct drm_i915_private *dev_priv,
> > return bi->psf_bw[psf_gv_point];
> > }
> >
> > +static unsigned int icl_qgv_bw(struct drm_i915_private *i915,
> > + int num_active_planes, int qgv_point)
> > +{
> > + unsigned int idx;
> > +
> > + if (DISPLAY_VER(i915) >= 12)
> > + idx = tgl_max_bw_index(i915, num_active_planes, qgv_point);
> > + else
> > + idx = icl_max_bw_index(i915, num_active_planes, qgv_point);
> > +
> > + if (idx >= ARRAY_SIZE(i915->display.bw.max))
> > + return 0;
> > +
> > + return i915->display.bw.max[idx].deratedbw[qgv_point];
> > +}
> > +
> > void intel_bw_init_hw(struct drm_i915_private *dev_priv)
> > {
> > if (!HAS_DISPLAY(dev_priv))
> > @@ -806,6 +822,35 @@ intel_atomic_get_bw_state(struct intel_atomic_state *state)
> > return to_intel_bw_state(bw_state);
> > }
> >
> > +static unsigned int icl_max_bw_qgv_point_mask(struct drm_i915_private *i915,
> > + int num_active_planes)
> > +{
> > + unsigned int num_qgv_points = i915->display.bw.max[0].num_qgv_points;
> > + unsigned int max_bw_point_mask = 0;
> > + unsigned int max_bw = 0;
> > + int i;
> > +
> > + for (i = 0; i < num_qgv_points; i++) {
> > + unsigned int max_data_rate =
> > + icl_qgv_bw(i915, num_active_planes, i);
> > +
> > + /*
> > + * We need to know which qgv point gives us
> > + * maximum bandwidth in order to disable SAGV
> > + * if we find that we exceed SAGV block time
> > + * with watermarks. By that moment we already
> > + * have those, as it is calculated earlier in
> > + * intel_atomic_check,
> > + */
> > + if (max_data_rate > max_bw) {
> > + max_bw_point_mask = BIT(i);
> > + max_bw = max_data_rate;
> > + }
> > + }
> > +
> > + return max_bw_point_mask;
> > +}
> > +
>
> Wondering, why we just don't call it "max_bw_point", of course "mask"
> could be applied to single point as well, however in most cases it still
> kind of implies that there are few of those, however we always find
> a single one here.
Okay.. For QGV max point, indeed we are finding point with max bw. So the name can be changed. I
think it can be changed before merging instead of floating another version - well if we these
patches can be RB-ed
Vinod
>
> Stan
>
> > static int mtl_find_qgv_points(struct drm_i915_private *i915,
> > unsigned int data_rate,
> > unsigned int num_active_planes,
> > @@ -883,8 +928,6 @@ static int icl_find_qgv_points(struct drm_i915_private *i915,
> > const struct intel_bw_state *old_bw_state,
> > struct intel_bw_state *new_bw_state)
> > {
> > - unsigned int max_bw_point = 0;
> > - unsigned int max_bw = 0;
> > unsigned int num_psf_gv_points = i915->display.bw.max[0].num_psf_gv_points;
> > unsigned int num_qgv_points = i915->display.bw.max[0].num_qgv_points;
> > u16 psf_points = 0;
> > @@ -897,31 +940,8 @@ static int icl_find_qgv_points(struct drm_i915_private *i915,
> > return ret;
> >
> > for (i = 0; i < num_qgv_points; i++) {
> > - unsigned int idx;
> > - unsigned int max_data_rate;
> > -
> > - if (DISPLAY_VER(i915) >= 12)
> > - idx = tgl_max_bw_index(i915, num_active_planes, i);
> > - else
> > - idx = icl_max_bw_index(i915, num_active_planes, i);
> > -
> > - if (idx >= ARRAY_SIZE(i915->display.bw.max))
> > - continue;
> > -
> > - max_data_rate = i915->display.bw.max[idx].deratedbw[i];
> > -
> > - /*
> > - * We need to know which qgv point gives us
> > - * maximum bandwidth in order to disable SAGV
> > - * if we find that we exceed SAGV block time
> > - * with watermarks. By that moment we already
> > - * have those, as it is calculated earlier in
> > - * intel_atomic_check,
> > - */
> > - if (max_data_rate > max_bw) {
> > - max_bw_point = i;
> > - max_bw = max_data_rate;
> > - }
> > + unsigned int max_data_rate = icl_qgv_bw(i915,
> > + num_active_planes, i);
> > if (max_data_rate >= data_rate)
> > qgv_points |= BIT(i);
> >
> > @@ -965,9 +985,9 @@ static int icl_find_qgv_points(struct drm_i915_private *i915,
> > * cause.
> > */
> > if (!intel_can_enable_sagv(i915, new_bw_state)) {
> > - qgv_points = BIT(max_bw_point);
> > - drm_dbg_kms(&i915->drm, "No SAGV, using single QGV point %d\n",
> > - max_bw_point);
> > + qgv_points = icl_max_bw_qgv_point_mask(i915, num_active_planes);
> > + drm_dbg_kms(&i915->drm, "No SAGV, using single QGV point mask 0x%x\n",
> > + qgv_points);
> > }
> >
> > /*
> > --
> > 2.34.1
> >
