[SRU][R][PATCH 11/13] drm/i915/backlight: Provide clear description on how backlight level is controlled

[Werner Sembach]

From: Suraj Kandpal <suraj.kandpal at intel.com>

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 at intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy at intel.com>
Link: https://patch.msgid.link/20260302040613.3324049-8-suraj.kandpal@intel.com
Signed-off-by: Werner Sembach <wse at tuxedocomputers.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 4d6ef1dca4a79..d0c76632a946a 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;
-- 
2.43.0