On Mon, Aug 31, 2015 at 11:23:28AM +0300, Ander Conselvan de Oliveira wrote: > The DP MST encoder config function never sets ddi_pll_sel, even though > its value is programmed in its ->pre_enable() hook. That used to work > because a new pipe_config was kzalloc'ed at every modeset, and the value > of zero selects the highest clock for the PLL. Starting with the commit > below, the value of ddi_pll_sel is preserved through modesets, and since > the correct value wasn't properly setup by the MST code, it could lead > to warnings and blank screens. The ddi pll handling is still quite a mess. Every platform does things just a bit different to the next guy. But yeah, looks like HSW/BDW handle the PLL selection for DP from the encoder .compute_config() so MST should do the same since it (re)computes the main link config for each stream. And SKL and BXT handle DP via the .crtc_compute_clock() path, so nothing needed for them I suppose. Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > commit 8504c74c7ae48b4b8ed1f1c0acf67482a7f45c93 > Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx> > Date: Fri May 15 11:51:50 2015 +0300 > > drm/i915: Preserve ddi_pll_sel when allocating new pipe_config > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91628 > Cc: stable@xxxxxxxxxxxxxxx > Cc: Timo Aaltonen <tjaalton@xxxxxxxxxx> > Cc: Luciano Coelho <luciano.coelho@xxxxxxxxx> > Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_dp.c | 2 +- > drivers/gpu/drm/i915/intel_dp_mst.c | 5 +++++ > drivers/gpu/drm/i915/intel_drv.h | 1 + > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 9e90a2b..393aed0 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -1190,7 +1190,7 @@ skl_edp_set_pll_config(struct intel_crtc_state *pipe_config) > pipe_config->dpll_hw_state.ctrl1 = ctrl1; > } > > -static void > +void > hsw_dp_set_ddi_pll_sel(struct intel_crtc_state *pipe_config) > { > memset(&pipe_config->dpll_hw_state, 0, > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c > index ebf2054..677d70e 100644 > --- a/drivers/gpu/drm/i915/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c > @@ -33,6 +33,7 @@ > static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, > struct intel_crtc_state *pipe_config) > { > + struct drm_device *dev = encoder->base.dev; > struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base); > struct intel_digital_port *intel_dig_port = intel_mst->primary; > struct intel_dp *intel_dp = &intel_dig_port->dp; > @@ -88,6 +89,10 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, > &pipe_config->dp_m_n); > > pipe_config->dp_m_n.tu = slots; > + > + if (IS_HASWELL(dev) || IS_BROADWELL(dev)) > + hsw_dp_set_ddi_pll_sel(pipe_config); > + > return true; > > } > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index c61ba47..458f56c 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -1209,6 +1209,7 @@ void intel_edp_drrs_disable(struct intel_dp *intel_dp); > void intel_edp_drrs_invalidate(struct drm_device *dev, > unsigned frontbuffer_bits); > void intel_edp_drrs_flush(struct drm_device *dev, unsigned frontbuffer_bits); > +void hsw_dp_set_ddi_pll_sel(struct intel_crtc_state *pipe_config); > > /* intel_dp_mst.c */ > int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id); > -- > 2.4.3 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel OTC -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html