On Tue, Feb 07, 2023 at 08:43:37AM +0200, Ville Syrjala 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. > It looks like CC: stable was added while merging this patch. But it doesn't go clean. build fails due to s/dev_priv/i915 and also due to the lack of ICP_SECOND_PPS_IO_SELECT that was added by another patch. So we need a backported version of this patch to be included in the stable trees... how far we will go in the stable tree? At this point of -rc7 I even wonder it will be better to stay for 6.2 to get released and then send the backported version to the stable ml directly... > 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; > +} > + > +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; > + > + 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)); > -- > 2.39.1 >
