[PATCH v3 11/13] drm/i915/backlight: Use drm helper to initialize edp backlight

[Kandpal, Suraj]

> -----Original Message-----
> From: Murthy, Arun R <arun.r.murthy at intel.com>
> Sent: Tuesday, June 24, 2025 10:31 AM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-xe at lists.freedesktop.org;
> intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
> nouveau at lists.freedesktop.org
> Subject: RE: [PATCH v3 11/13] drm/i915/backlight: Use drm helper to initialize
> edp backlight
> 
> > > > -----Original Message-----
> > > > From: Kandpal, Suraj <suraj.kandpal at intel.com>
> > > > Sent: Friday, June 20, 2025 12:05 PM
> > > > To: intel-xe at lists.freedesktop.org;
> > > > intel-gfx at lists.freedesktop.org;
> > > > dri- devel at lists.freedesktop.org; nouveau at lists.freedesktop.org
> > > > Cc: Murthy, Arun R <arun.r.murthy at intel.com>; Kandpal, Suraj
> > > > <suraj.kandpal at intel.com>
> > > > Subject: [PATCH v3 11/13] drm/i915/backlight: Use drm helper to
> > > > initialize edp backlight
> > > >
> > > > Now that drm_edp_backlight init has been modified to take into
> > > > account the setup of lumininace based brightness manipulation we
> > > > can just use
> > > that.
> > > >
> > > > --v2
> > > > -Fix commit message [Arun]
> > > >
> > > > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > > > ---
> > > >  .../drm/i915/display/intel_dp_aux_backlight.c | 98
> > > > +++++++++----------
> > > >  1 file changed, 48 insertions(+), 50 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 800d07c7f041..117c762fa2fe 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > > > @@ -584,9 +584,37 @@ static int
> > > > intel_dp_aux_vesa_setup_backlight(struct
> > > > intel_connector *connector,
> > > >  	u8 current_mode;
> > > >  	int ret;
> > > >
> > > > -	if (panel->backlight.edp.vesa.luminance_control_support) {
> > > > +	ret = drm_edp_backlight_init(&intel_dp->aux, &panel-
> > > > >backlight.edp.vesa.info,
> > > > +				     luminance_range->max_luminance,
> > > > +				     panel->vbt.backlight.pwm_freq_hz,
> > > > +				     intel_dp->edp_dpcd, &current_level,
> > > > &current_mode,
> > > > +				     false);
> > > > +	if (ret < 0)
> > > > +		return ret;
> > > > +
> > > > +	drm_dbg_kms(display->drm,
> > > > +		    "[CONNECTOR:%d:%s] AUX VESA backlight enable is
> > > > controlled through %s\n",
> > > > +		    connector->base.base.id, connector->base.name,
> > > > +		    dpcd_vs_pwm_str(panel-
> > > > >backlight.edp.vesa.info.aux_enable));
> > > > +	drm_dbg_kms(display->drm,
> > > > +		    "[CONNECTOR:%d:%s] AUX VESA backlight level is
> > > controlled
> > > > through %s\n",
> > > > +		    connector->base.base.id, connector->base.name,
> > > > +		    dpcd_vs_pwm_str(panel-
> > > >backlight.edp.vesa.info.aux_set));
> > > > +
> > > Can these both debug prints be combined?
> > >
> >
> > One talks about backlight enable and other about backlight level do
> > you still Want to combine them ?
> >
> Yes, can replace with "enable and level controlled by"

Could be that it is enabled through DPCD but controlled through PWM that's why it uses
Aux_enable and aux_set to decide when to print dpcd vs pwm

Regards,
Suraj Kandpal

> 
> Thanks and Regards,
> Arun R Murthy
> --------------------