On Tue, 07 Feb 2023, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Use the second backlight controller on ICP+ if the VBT asks > us to do so. > > On pre-MTP we also check the chicken bit to make sure the > pins have been correctly muxed by the firmware. > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8016 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > --- > .../gpu/drm/i915/display/intel_backlight.c | 34 +++++++++++++++++-- > 1 file changed, 31 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c > index 5b7da72c95b8..a4e4b7f79e4d 100644 > --- a/drivers/gpu/drm/i915/display/intel_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_backlight.c > @@ -1431,6 +1431,30 @@ bxt_setup_backlight(struct intel_connector *connector, enum pipe unused) > return 0; > } > > +static int cnp_num_backlight_controllers(struct drm_i915_private *i915) > +{ > + if (INTEL_PCH_TYPE(i915) >= PCH_DG1) > + return 1; > + > + if (INTEL_PCH_TYPE(i915) >= PCH_ICP) > + return 2; > + > + return 1; > +} At some point I think we should clean this up between backlight and pps. There's already intel_num_pps(). But let's get this merged as-is now. > + > +static bool cnp_backlight_controller_is_valid(struct drm_i915_private *i915, int controller) > +{ > + if (controller < 0 || controller >= cnp_num_backlight_controllers(i915)) > + return false; > + > + if (controller == 1 && > + INTEL_PCH_TYPE(i915) >= PCH_ICP && > + INTEL_PCH_TYPE(i915) < PCH_MTP) > + return intel_de_read(i915, SOUTH_CHICKEN1) & ICP_SECOND_PPS_IO_SELECT; I got a bit confused that MTP has two controllers but it doesn't have that bit. I first thought you were off by one with that < PCH_MTP. But looks like it's correct. Anyway, Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> > + > + return true; > +} > + > static int > cnp_setup_backlight(struct intel_connector *connector, enum pipe unused) > { > @@ -1440,10 +1464,14 @@ cnp_setup_backlight(struct intel_connector *connector, enum pipe unused) > > /* > * CNP has the BXT implementation of backlight, but with only one > - * controller. TODO: ICP has multiple controllers but we only use > - * controller 0 for now. > + * controller. ICP+ can have two controllers, depending on pin muxing. > */ > - panel->backlight.controller = 0; > + panel->backlight.controller = connector->panel.vbt.backlight.controller; > + if (!cnp_backlight_controller_is_valid(i915, panel->backlight.controller)) { > + drm_dbg_kms(&i915->drm, "Invalid backlight controller %d, assuming 0\n", > + panel->backlight.controller); > + panel->backlight.controller = 0; > + } > > pwm_ctl = intel_de_read(i915, > BXT_BLC_PWM_CTL(panel->backlight.controller)); -- Jani Nikula, Intel Open Source Graphics Center
