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

[Murthy, Arun R]

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.

+       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;