On Tue, Aug 29, 2023 at 01:34:56PM +0000, Govindapillai, Vinod wrote:
> On Tue, 2023-08-29 at 10:50 +0300, Ville Syrjälä wrote:
> > On Mon, Aug 28, 2023 at 09:20:34AM +0300, Vinod Govindapillai wrote:
> > > In LNL onwards, FBC can be associated to the first three planes.
> > > The FBC will be enabled for first FBC capable visible plane
> > > until the userspace can select one of these FBC capable plane
> > > explicitly
> > >
> > > Bspec: 69560
> > > Signed-off-by: Vinod Govindapillai <vinod.govindapillai@xxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_fbc.c | 29 +++++++++++++++++++
> > > .../drm/i915/display/skl_universal_plane.c | 5 +++-
> > > drivers/gpu/drm/i915/i915_reg.h | 4 +++
> > > 3 files changed, 37 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> > > index 45e205a0f740..62f59630d410 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> > > @@ -649,6 +649,21 @@ static void skl_fbc_program_cfb_stride(struct intel_fbc *fbc)
> > > CHICKEN_FBC_STRIDE_MASK, val);
> > > }
> > >
> > > +static u32 lnl_plane_binding(struct intel_fbc *fbc)
> > > +{
> > > + switch (fbc->state.plane->id) {
> > > + default:
> > > + MISSING_CASE(fbc->state.plane->id);
> > > + fallthrough;
> > > + case 0:
> > > + return DPFC_CTL_PLANE_BINDING_1;
> > > + case 1:
> > > + return DPFC_CTL_PLANE_BINDING_2;
> > > + case 2:
> > > + return DPFC_CTL_PLANE_BINDING_3;
> > > + }
> > > +}
> > > +
> > > static u32 ivb_dpfc_ctl(struct intel_fbc *fbc)
> > > {
> > > const struct intel_fbc_state *fbc_state = &fbc->state;
> > > @@ -660,6 +675,9 @@ static u32 ivb_dpfc_ctl(struct intel_fbc *fbc)
> > > if (IS_IVYBRIDGE(i915))
> > > dpfc_ctl |= DPFC_CTL_PLANE_IVB(fbc_state->plane->i9xx_plane);
> > >
> > > + if (DISPLAY_VER(i915) >= 20)
> > > + dpfc_ctl |= lnl_plane_binding(fbc);
> > > +
> > > if (fbc_state->fence_id >= 0)
> > > dpfc_ctl |= DPFC_CTL_FENCE_EN_IVB;
> > >
> > > @@ -1250,6 +1268,17 @@ static int intel_fbc_check_plane(struct intel_atomic_state *state,
> > > }
> > > }
> > >
> > > + /*
> > > + * From LNL, FBC can be assigned on any plane. Until a provision is
> > > + * provided for the userspace to select a plane for FBC, lets select
> > > + * the first visible plane that is FBC capable.
> > > + */
> > > + if (DISPLAY_VER(i915) >= 20 && fbc->state.plane &&
> > > + fbc->state.plane != plane) {
> > > + plane_state->no_fbc_reason = "fbc enabled on another plane";
> > > + return 0;
> > > + }
> >
> > This isn't right. fbc->state.plane is an internal state thing
> > that chanes willy nilly, so we don't want to check it here.
> >
> > But we shouldn't need this kind of check anyway. The code
> > should already work just fine if you just do the tweak to
> > skl_plane_has_fbc((). Which plane actually gets FBC will be
> > a bit random, but I think that's fine for the moment.
>
> Currently, intel_crtc_init() creates the primary plane and other planes. Then the "fbc" is
> associated with the primary plane based on skl_plane_has_fbc()
>
> In Lnl, the first 3 planes are FBC capable. So my thinking has been that those three planes can have
> the fbc pointers.
>
> And because at the moment we don't have a logic to select which frame should get this FBC,
It's there (in intel_fbc_update()/__intel_fbc_enable() more or
less). It's just "first come first serve".
> I used
> the above snippet to avoid FBC being assoicated with multiple planes in a pipe. So the first visible
> fbc capable plane will had no_fbc_reason as NULL and the other 2 planes will have "fbc on another
> plane".
>
> BR
> Vinod
>
> >
> > > +
> > > plane_state->no_fbc_reason = NULL;
> > >
> > > return 0;
> > > diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > > b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > > index 4d01c7ae4485..1291351c9941 100644
> > > --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > > +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > > @@ -1962,7 +1962,10 @@ static bool skl_plane_has_fbc(struct drm_i915_private *dev_priv,
> > > if ((DISPLAY_RUNTIME_INFO(dev_priv)->fbc_mask & BIT(fbc_id)) == 0)
> > > return false;
> > >
> > > - return plane_id == PLANE_PRIMARY;
> > > + if (DISPLAY_VER(dev_priv) >= 20)
> > > + return plane_id <= PLANE_SPRITE1;
> > > + else
> > > + return plane_id == PLANE_PRIMARY;
> > > }
> > >
> > > static struct intel_fbc *skl_plane_fbc(struct drm_i915_private *dev_priv,
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > > index aefad14ab27a..b207774f3c33 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -1327,6 +1327,10 @@
> > > #define DPFC_CTL_PLANE_IVB(i9xx_plane) REG_FIELD_PREP(DPFC_CTL_PLANE_MASK_IVB,
> > > (i9xx_plane))
> > > #define DPFC_CTL_FENCE_EN_IVB REG_BIT(28) /* ivb+ */
> > > #define DPFC_CTL_PERSISTENT_MODE REG_BIT(25) /* g4x-snb */
> > > +#define DPFC_CTL_PLANE_BINDING_MASK REG_GENMASK(12, 11) /* XE */
> > > +#define DPFC_CTL_PLANE_BINDING_1 REG_FIELD_PREP(DPFC_CTL_PLANE_BINDING_MASK, 0)
> > > /* XE */
> > > +#define DPFC_CTL_PLANE_BINDING_2 REG_FIELD_PREP(DPFC_CTL_PLANE_BINDING_MASK, 1)
> > > /* XE */
> > > +#define DPFC_CTL_PLANE_BINDING_3 REG_FIELD_PREP(DPFC_CTL_PLANE_BINDING_MASK, 2)
> > > /* XE */
> > > #define DPFC_CTL_FALSE_COLOR REG_BIT(10) /* ivb+ */
> > > #define DPFC_CTL_SR_EN REG_BIT(10) /* g4x only */
> > > #define DPFC_CTL_SR_EXIT_DIS REG_BIT(9) /* g4x only */
> > > --
> > > 2.34.1
> >
>
--
Ville Syrjälä
Intel
