On Tue, 2021-10-05 at 20:56 +0300, Jani Nikula wrote: > For the time being, neither the power sequencer nor the backlight code > properly support two eDP panels simultaneously. While the software > states will be independent, the same sets of registers will be used for > both eDP panels, clobbering the hardware state and leading to errors. > > Gracefully disable dual eDP until proper support has been added. > > Cc: José Roberto de Souza <jose.souza@xxxxxxxxx> > Cc: Uma Shankar <uma.shankar@xxxxxxxxx> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Cc: Swati Sharma <swati2.sharma@xxxxxxxxx> > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> > --- > drivers/gpu/drm/i915/display/intel_bios.c | 47 +++++++++++++++++++++++ > 1 file changed, 47 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c > index f9776ca85de3..b99907c656bb 100644 > --- a/drivers/gpu/drm/i915/display/intel_bios.c > +++ b/drivers/gpu/drm/i915/display/intel_bios.c > @@ -1930,6 +1930,50 @@ static int _intel_bios_max_tmds_clock(const struct intel_bios_encoder_data *devd > } > } > > +static enum port get_edp_port(struct drm_i915_private *i915) > +{ > + const struct intel_bios_encoder_data *devdata; > + enum port port; > + > + for_each_port(port) { > + devdata = i915->vbt.ports[port]; > + > + if (devdata && intel_bios_encoder_supports_edp(devdata)) > + return port; > + } > + > + return PORT_NONE; > +} > + > +/* > + * FIXME: The power sequencer and backlight code currently do not support more > + * than one set registers, at least not on anything other than VLV/CHV. It will > + * clobber the registers. As a temporary workaround, gracefully prevent more > + * than one eDP from being registered. > + */ > +static void sanitize_dual_edp(struct intel_bios_encoder_data *devdata, > + enum port port) > +{ > + struct drm_i915_private *i915 = devdata->i915; > + struct child_device_config *child = &devdata->child; > + enum port p; > + > + /* CHV might not clobber PPS registers. */ > + if (IS_CHERRYVIEW(i915)) > + return; > + > + p = get_edp_port(i915); > + if (p == PORT_NONE) > + return; > + > + drm_dbg_kms(&i915->drm, "both ports %c and %c configured as eDP, " > + "disabling port %c eDP\n", port_name(p), port_name(port), > + port_name(port)); > + > + child->device_type &= ~DEVICE_TYPE_DISPLAYPORT_OUTPUT; Why also cleaning the DEVICE_TYPE_DISPLAYPORT_OUTPUT bit? The rest lgtm. > + child->device_type &= ~DEVICE_TYPE_INTERNAL_CONNECTOR; > +} > + > static bool is_port_valid(struct drm_i915_private *i915, enum port port) > { > /* > @@ -1987,6 +2031,9 @@ static void parse_ddi_port(struct drm_i915_private *i915, > supports_typec_usb, supports_tbt, > devdata->dsc != NULL); > > + if (is_edp) > + sanitize_dual_edp(devdata, port); > + > if (is_dvi) > sanitize_ddc_pin(devdata, port); >