> Subject: [PATCH] drm/i915: Try to preserve the current shared_dpll for fastset > on type-c ports > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Currently icl_compute_tc_phy_dplls() assumes that the active PLL will be the > TC PLL (as opposed to the TBT PLL). The actual PLL will be selected during the > modeset enable sequence, but we need to put *something* into the > crtc_state->shared_dpll already during compute_config(). > > The downside of assuming one PLL or the other is that we'll fail to fastset if the > assumption doesn't match what was in use previously. So let's instead keep > the same PLL that was in use previously (assuming there was one). This should > allow fastset to work again when using TBT PLL, at least in the steady state. > > Now, assuming we want keep the same PLL may not be entirely correct either. > But we should be covered by the typ-c link reset handling which will force a full Small typo *type-c > modeset by flagging connectors_changed=true which means the resulting > modeset can't be converted into a fastset even if the full crtc state looks > identical. > > Cc: Imre Deak <imre.deak@xxxxxxxxx> > Cc: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> LGTM. Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> > --- > drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c > b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c > index ef57dad1a9cb..1008e18177c9 100644 > --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c > +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c > @@ -3308,6 +3308,8 @@ static int icl_compute_tc_phy_dplls(struct > intel_atomic_state *state, > struct drm_i915_private *i915 = to_i915(state->base.dev); > struct intel_crtc_state *crtc_state = > intel_atomic_get_new_crtc_state(state, crtc); > + const struct intel_crtc_state *old_crtc_state = > + intel_atomic_get_old_crtc_state(state, crtc); > struct icl_port_dpll *port_dpll = > &crtc_state->icl_port_dplls[ICL_PORT_DPLL_DEFAULT]; > struct skl_wrpll_params pll_params = {}; @@ -3326,7 +3328,11 @@ > static int icl_compute_tc_phy_dplls(struct intel_atomic_state *state, > return ret; > > /* this is mainly for the fastset check */ > - icl_set_active_port_dpll(crtc_state, ICL_PORT_DPLL_MG_PHY); > + if (old_crtc_state->shared_dpll && > + old_crtc_state->shared_dpll->info->id == DPLL_ID_ICL_TBTPLL) > + icl_set_active_port_dpll(crtc_state, ICL_PORT_DPLL_DEFAULT); > + else > + icl_set_active_port_dpll(crtc_state, > ICL_PORT_DPLL_MG_PHY); > > crtc_state->port_clock = icl_ddi_mg_pll_get_freq(i915, NULL, > &port_dpll- > >hw_state); > -- > 2.41.0