On Tue, Oct 05, 2021 at 10:40:14PM -0400, Lyude Paul wrote: > This simply adds proper support for panel backlights that can be controlled > via VESA's backlight control protocol, but which also require that we > enable and disable the backlight via PWM instead of via the DPCD interface. > We also enable this by default, in order to fix some people's backlights > that were broken by not having this enabled. > > For reference, backlights that require this and use VESA's backlight > interface tend to be laptops with hybrid GPUs, but this very well may > change in the future. > > Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> > Link: https://gitlab.freedesktop.org/drm/intel/-/issues/3680 > Fixes: fe7d52bccab6 ("drm/i915/dp: Don't use DPCD backlights that need PWM enable/disable") > Cc: <stable@xxxxxxxxxxxxxxx> # v5.12+ > --- > .../drm/i915/display/intel_dp_aux_backlight.c | 24 ++++++++++++++----- > 1 file changed, 18 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > index 569d17b4d00f..594fdc7453ca 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > @@ -293,6 +293,10 @@ intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state, > struct intel_panel *panel = &connector->panel; > struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > > + if (!panel->backlight.edp.vesa.info.aux_enable) > + panel->backlight.pwm_funcs->enable(crtc_state, conn_state, > + panel->backlight.pwm_level_max); What't the story here with the non-inverted max vs. pontetially inverted 0 in the counterpart? > + > drm_edp_backlight_enable(&intel_dp->aux, &panel->backlight.edp.vesa.info, level); > } > > @@ -304,6 +308,10 @@ static void intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state > struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > > drm_edp_backlight_disable(&intel_dp->aux, &panel->backlight.edp.vesa.info); > + > + if (!panel->backlight.edp.vesa.info.aux_enable) > + panel->backlight.pwm_funcs->disable(old_conn_state, > + intel_backlight_invert_pwm_level(connector, 0)); > } > > static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, enum pipe pipe) > @@ -321,6 +329,15 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, > if (ret < 0) > return ret; > > + if (!panel->backlight.edp.vesa.info.aux_enable) { > + ret = panel->backlight.pwm_funcs->setup(connector, pipe); > + if (ret < 0) { > + drm_err(&i915->drm, > + "Failed to setup PWM backlight controls for eDP backlight: %d\n", > + ret); > + return ret; > + } > + } > panel->backlight.max = panel->backlight.edp.vesa.info.max; > panel->backlight.min = 0; > if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { > @@ -340,12 +357,7 @@ intel_dp_aux_supports_vesa_backlight(struct intel_connector *connector) > struct intel_dp *intel_dp = intel_attached_dp(connector); > struct drm_i915_private *i915 = dp_to_i915(intel_dp); > > - /* TODO: We currently only support AUX only backlight configurations, not backlights which > - * require a mix of PWM and AUX controls to work. In the mean time, these machines typically > - * work just fine using normal PWM controls anyway. > - */ > - if ((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) && > - drm_edp_backlight_supported(intel_dp->edp_dpcd)) { > + if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) { > drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n"); > return true; > } > -- > 2.31.1 -- Ville Syrjälä Intel