oh hold on, I misspoke. Here's the patch I was thinking of: https://patchwork.freedesktop.org/series/82041/ On Thu, 2020-10-08 at 10:32 +0800, Kai-Heng Feng wrote: > Hi Lyude, > > > On Oct 8, 2020, at 05:53, Lyude Paul <lyude@xxxxxxxxxx> wrote: > > > > Hi! I thought this patch rang a bell, we actually already had some > > discussion > > about this since there's a couple of other systems this was causing issues > > for. > > Unfortunately it never seems like that patch got sent out. Satadru? > > > > (if I don't hear back from them soon, I'll just send out a patch for this > > myself) > > > > JFYI - the proper fix here is to just drop the > > DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP check from the code entirely. As > > long as > > the backlight supports AUX_SET_CAP, that should be enough for us to control > > it. > > Does the proper fix include dropping DP_QUIRK_FORCE_DPCD_BACKLIGHT entirely? > > Kai-Heng > > > > > On Wed, 2020-10-07 at 14:58 +0800, Kai-Heng Feng wrote: > > > HP DreamColor panel needs to be controlled via AUX interface. However, > > > it has both DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP and > > > DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP set, so it fails to pass > > > intel_dp_aux_display_control_capable() test. > > > > > > Skip the test if the panel has force DPCD quirk. > > > > > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 10 ++++++---- > > > 1 file changed, 6 insertions(+), 4 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 acbd7eb66cbe..acf2e1c65290 100644 > > > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > > > @@ -347,9 +347,13 @@ int intel_dp_aux_init_backlight_funcs(struct > > > intel_connector *intel_connector) > > > struct intel_panel *panel = &intel_connector->panel; > > > struct intel_dp *intel_dp = enc_to_intel_dp(intel_connector->encoder); > > > struct drm_i915_private *i915 = dp_to_i915(intel_dp); > > > + bool force_dpcd; > > > + > > > + force_dpcd = drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks, > > > + DP_QUIRK_FORCE_DPCD_BACKLIGHT); > > > > > > if (i915->params.enable_dpcd_backlight == 0 || > > > - !intel_dp_aux_display_control_capable(intel_connector)) > > > + (!force_dpcd && > > > !intel_dp_aux_display_control_capable(intel_connector))) > > > return -ENODEV; > > > > > > /* > > > @@ -358,9 +362,7 @@ int intel_dp_aux_init_backlight_funcs(struct > > > intel_connector *intel_connector) > > > */ > > > if (i915->vbt.backlight.type != > > > INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE && > > > - i915->params.enable_dpcd_backlight != 1 && > > > - !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks, > > > - DP_QUIRK_FORCE_DPCD_BACKLIGHT)) { > > > + i915->params.enable_dpcd_backlight != 1 && !force_dpcd) { > > > drm_info(&i915->drm, > > > "Panel advertises DPCD backlight support, but " > > > "VBT disagrees. If your backlight controls " > > -- > > Sincerely, > > Lyude Paul (she/her) > > Software Engineer at Red Hat -- Sincerely, Lyude Paul (she/her) Software Engineer at Red Hat _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
