> -----Original Message-----
> From: Kandpal, Suraj <suraj.kand...@intel.com>
> Sent: Monday, April 14, 2025 9:46 AM
> To: nouveau@lists.freedesktop.org; dri-de...@lists.freedesktop.org; intel-
> x...@lists.freedesktop.org; intel-...@lists.freedesktop.org
> Cc: Nautiyal, Ankit K <ankit.k.nauti...@intel.com>; Murthy, Arun R
> <arun.r.mur...@intel.com>; Kandpal, Suraj <suraj.kand...@intel.com>
> Subject: [PATCH 01/13] drm/dp: Introduce new member in drm_backlight_info
>
> Introduce luminance_set flag which indicates if we can manipulate backlight
> using luminance value or not which is only possible after eDP v1.5.
>
> Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
> ---
Reviewed-by: Arun R Murthy <arun.r.mur...@intel.com>
Thanks and Regards,
Arun R Murthy
-------------------
> drivers/gpu/drm/display/drm_dp_helper.c | 8 ++++++--
> include/drm/display/drm_dp_helper.h | 1 +
> 2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
> b/drivers/gpu/drm/display/drm_dp_helper.c
> index 57828f2b7b5a..41de7a92d76d 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -4253,11 +4253,15 @@ drm_edp_backlight_init(struct drm_dp_aux *aux,
> struct drm_edp_backlight_info *bl
> bl->aux_set = true;
> if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
> bl->lsb_reg_used = true;
> + if ((edp_dpcd[0] & DP_EDP_15) && edp_dpcd[3] &
> + (DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE))
> + bl->luminance_set = true;
>
> /* Sanity check caps */
> - if (!bl->aux_set && !(edp_dpcd[2] &
> DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) {
> + if (!bl->aux_set && !(edp_dpcd[2] &
> DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP) &&
> + !bl->luminance_set) {
> drm_dbg_kms(aux->drm_dev,
> - "%s: Panel supports neither AUX or PWM brightness
> control? Aborting\n",
> + "%s: Panel does not support AUX, PWM or
> luminance-based
> +brightness control. Aborting\n",
> aux->name);
> return -EINVAL;
> }
> diff --git a/include/drm/display/drm_dp_helper.h
> b/include/drm/display/drm_dp_helper.h
> index d9614e2c8939..b8fdc09737fc 100644
> --- a/include/drm/display/drm_dp_helper.h
> +++ b/include/drm/display/drm_dp_helper.h
> @@ -844,6 +844,7 @@ struct drm_edp_backlight_info {
> bool lsb_reg_used : 1;
> bool aux_enable : 1;
> bool aux_set : 1;
> + bool luminance_set : 1;
> };
>
> int
> --
> 2.34.1
