> -----Original Message-----
> From: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Sent: Tuesday, February 4, 2025 2:15 PM
> To: Kandpal, Suraj <suraj.kandpal@xxxxxxxxx>; intel-xe@xxxxxxxxxxxxxxxxxxxxx;
> intel-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Shankar, Uma <uma.shankar@xxxxxxxxx>; Murthy, Arun R
> <arun.r.murthy@xxxxxxxxx>; Kao, Ben <ben.kao@xxxxxxxxx>; Kandpal, Suraj
> <suraj.kandpal@xxxxxxxxx>
> Subject: Re: [PATCH 3/7] drm/i915/backlight: Check Nits based brightness
> control for VESA
>
> On Fri, 24 Jan 2025, Suraj Kandpal <suraj.kandpal@xxxxxxxxx> wrote:
> > Check if we are capable of controlling brightness via Nits which is
> > dependant on PANEL_LUMINANCE_OVERRIDE and SMOOTH_BRIGHTNESS
> > capablility being set.
> >
> > Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/intel_display_types.h | 1 +
> > drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 9 +++++++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index 083eb86f0904..f900e1f2d93e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -412,6 +412,7 @@ struct intel_panel {
> > union {
> > struct {
> > struct drm_edp_backlight_info info;
> > + bool nits_support;
> > } vesa;
> > struct {
> > bool sdr_uses_aux;
> > 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 09e82f24d030..c5ff6e044866 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > @@ -575,6 +575,15 @@ intel_dp_aux_supports_vesa_backlight(struct
> > intel_connector *connector) {
> > struct intel_display *display = to_intel_display(connector);
> > struct intel_dp *intel_dp = intel_attached_dp(connector);
> > + struct intel_panel *panel = &connector->panel;
> > +
> > + if ((intel_dp->edp_dpcd[2] &
> DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE)) {
> > + drm_dbg_kms(display->drm,
> > + "[CONNECTOR:%d:%s] AUX Nits Based Backlight
> Control Supported!\n",
> > + connector->base.base.id, connector->base.name);
> > + panel->backlight.edp.vesa.nits_support = true;
>
> Should we refer to luminance rather than nits here?
Sure I can refactor the series to use luminance over nits then
Regards,
Suraj Kandpal
>
> BR,
> Jani.
>
>
> > + return true;
> > + }
> >
> > if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
> > drm_dbg_kms(display->drm,
>
> --
> Jani Nikula, Intel
