From: Suraj Kandpal <suraj.kandpal@intel.com>
Date: Mon, 2 Mar 2026 04:06:12 +0000 (+0530)
Subject: drm/i915/backlight: Provide clear description on how backlight level is controlled
X-Git-Tag: v7.1-rc1~167^2~24^2~79
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7dbfba0ba0b99661266c93cd9025d47197241511;p=thirdparty%2Flinux.git

drm/i915/backlight: Provide clear description on how backlight level is controlled

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.kandpal@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Link: https://patch.msgid.link/20260302040613.3324049-8-suraj.kandpal@intel.com
---

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 8d3f114a458b1..a7b186d0e3c47 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 %";
+	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) {
@@ -567,9 +579,6 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
 		}
 		panel->backlight.level = intel_dp_aux_vesa_get_backlight(connector, 0);
 		panel->backlight.enabled = panel->backlight.level != 0;
-		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;