On Wed, Aug 16, 2017 at 01:19:51PM -0700, Rodrigo Vivi wrote: > Sequences for DisplayPort asks us to > " Configure voltage swing and related IO settings. > Refer to DDI Buffer section." > > before "Configure and enable DDI_BUF_CTL" > > On BXT and CNL this means to execute the ddi vswing sequences. > > At this point these sequences calls are getting duplicated for DP > because they are all called from DP link trainning sequences. > > However this patch is not yet removing it before a futher discussion > since spec also allows that during link training without disabling > anything: > > " > Notes > Changing voltage swing during link training: > Change the swing setting following the DDI Buffer section. > The port does not need to be disabled. > " > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_ddi.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > index a6056bb4f801..8ea0368e15b1 100644 > --- a/drivers/gpu/drm/i915/intel_ddi.c > +++ b/drivers/gpu/drm/i915/intel_ddi.c > @@ -2133,6 +2133,7 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > enum port port = intel_ddi_get_encoder_port(encoder); > struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base); > + uint32_t level = intel_ddi_dp_level(intel_dp); > > WARN_ON(link_mst && (port == PORT_A || port == PORT_E)); > > @@ -2145,7 +2146,11 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain); > > - if (!IS_GEN9_LP(dev_priv) && !IS_CANNONLAKE(dev_priv)) > + if (IS_CANNONLAKE(dev_priv)) > + cnl_ddi_vswing_sequence(encoder, level); > + else if (IS_GEN9_LP(dev_priv)) > + bxt_ddi_vswing_sequence(dev_priv, level, port, encoder->type); Hmm. Yeah, I guess it would make sense to set these up already before we enable DDI_BUF_CTL, which I think would happend from the .prepare_link_retrain() hook on DDI, and that does get called before the signal levels have been set up. So I'm fine with this change. Imre, any thoughts? > + else > intel_prepare_dp_ddi_buffers(encoder); > > intel_ddi_init_dp_buf_reg(encoder); > -- > 2.13.2 -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
