RE: [PATCH 7/8] drm/i915/backlight: Provide clear description on how backlight level is controlled

[Kandpal, Suraj]

> Subject: Re: [PATCH 7/8] drm/i915/backlight: Provide clear description on how
> backlight level is controlled
> 
> On 20-02-2026 10:32, Suraj Kandpal wrote:
> > Currently it takes us multiple log prints to arrive at the conclusion
> > on how we are actually controlling backlight level. Make the logging
> > concise.
> >
> > Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
> > ---
> >   .../drm/i915/display/intel_dp_aux_backlight.c | 19 ++++++++++++++-----
> >   1 file changed, 14 insertions(+), 5 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 043c9aef2ea6..aac6cdb5b69b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > @@ -368,6 +368,16 @@ static const char *dpcd_vs_pwm_str(bool aux)
> >     return aux ? "DPCD" : "PWM";
> >   }
> >
> > +static const char *backlight_unit_str(struct intel_panel *panel) {
> > +   if (panel->backlight.edp.vesa.info.luminance_set)
> > +           return "NITS";
> > +   else if (panel->backlight.edp.vesa.info.aux_set)
> > +           return "Brightness %";
> Should this be AUX Brightness?
> So that it calls out its AUX based DPCD backlight control.

Actually where this is called has the line
"AUX VESA backlight level is controlled through %s using %s values\n"
Here we return the unit value we use to control brightness

Regards,
Suraj Kandpal

> > +   else
> > +           return "PWM";
> > +}
> > +
> >   static void
> >   intel_dp_aux_write_panel_luminance_override(struct intel_connector
> *connector)
> >   {
> > @@ -542,9 +552,11 @@ static int
> intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
> >                 dpcd_vs_pwm_str(panel-
> >backlight.edp.vesa.info.aux_enable ||
> >                                 panel-
> >backlight.edp.vesa.info.luminance_set));
> >     drm_dbg_kms(display->drm,
> > -               "[CONNECTOR:%d:%s] AUX VESA backlight level is
> controlled through %s\n",
> > +               "[CONNECTOR:%d:%s] AUX VESA backlight level is
> controlled
> > +through %s using %s values\n",
> >                 connector->base.base.id, connector->base.name,
> > -               dpcd_vs_pwm_str(panel-
> >backlight.edp.vesa.info.aux_set));
> > +               dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_set
> ||
> > +                               panel-
> >backlight.edp.vesa.info.luminance_set),
> > +               backlight_unit_str(panel));
> >
> >     if (!panel->backlight.edp.vesa.info.aux_set ||
> >         !panel->backlight.edp.vesa.info.aux_enable) { @@ -569,9 +581,6
> > @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector
> *connector,
> >             panel->backlight.enabled = panel->backlight.level != 0;
> >             if (!panel->backlight.level)
> >                     panel->backlight.level = panel->backlight.max;
> > -           drm_dbg_kms(display->drm,
> > -                       "[CONNECTOR:%d:%s] AUX VESA Nits backlight
> level is controlled through DPCD\n",
> > -                       connector->base.base.id, connector->base.name);
> >     } else if (panel->backlight.edp.vesa.info.aux_set) {
> >             panel->backlight.max = panel->backlight.edp.vesa.info.max;
> >             panel->backlight.min = 0;