drm/i915: Make backlight setup debugs consistent

It's confusing to debug backlight issues when one can't
easily even tell what kind of backlight control was
selected. Sprinkle uniform debug messages to all the
backlight setup functions.

Also the one that was already there (ext_pwm) was
using drm_info() for some reason. I don't think that's
warranted so switch it to drm_dbg_kms() as well.

v2: Deal with AUX backlights too (Jani)
    Move the VLV/CHV initial pipe debug there too (Jani)

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230215135616.30411-1-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c
index a4e4b7f..cb1e442 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_backlight.c
@@ -1270,6 +1270,10 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus
                               cpu_ctl2 & ~BLM_PWM_ENABLE);
        }
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control\n",
+                   connector->base.base.id, connector->base.name);
+
        return 0;
 }
 
@@ -1297,6 +1301,10 @@ static int pch_setup_backlight(struct intel_connector *connector, enum pipe unus
        panel->backlight.pwm_enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
                (pch_ctl1 & BLM_PCH_PWM_ENABLE);
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control\n",
+                   connector->base.base.id, connector->base.name);
+
        return 0;
 }
 
@@ -1335,6 +1343,10 @@ static int i9xx_setup_backlight(struct intel_connector *connector, enum pipe unu
 
        panel->backlight.pwm_enabled = val != 0;
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PWM for backlight control\n",
+                   connector->base.base.id, connector->base.name);
+
        return 0;
 }
 
@@ -1364,6 +1376,10 @@ static int i965_setup_backlight(struct intel_connector *connector, enum pipe unu
 
        panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PWM for backlight control\n",
+                   connector->base.base.id, connector->base.name);
+
        return 0;
 }
 
@@ -1392,6 +1408,10 @@ static int vlv_setup_backlight(struct intel_connector *connector, enum pipe pipe
 
        panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PWM for backlight control (on pipe %c)\n",
+                   connector->base.base.id, connector->base.name, pipe_name(pipe));
+
        return 0;
 }
 
@@ -1428,6 +1448,11 @@ bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
 
        panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PWM for backlight control (controller=%d)\n",
+                   connector->base.base.id, connector->base.name,
+                   panel->backlight.controller);
+
        return 0;
 }
 
@@ -1490,6 +1515,11 @@ cnp_setup_backlight(struct intel_connector *connector, enum pipe unused)
 
        panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control (controller=%d)\n",
+                   connector->base.base.id, connector->base.name,
+                   panel->backlight.controller);
+
        return 0;
 }
 
@@ -1538,8 +1568,10 @@ static int ext_pwm_setup_backlight(struct intel_connector *connector,
                        NSEC_PER_SEC / get_vbt_pwm_freq(connector);
        }
 
-       drm_info(&i915->drm, "Using %s PWM for LCD backlight control\n",
-                desc);
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using %s PWM for backlight control\n",
+                   connector->base.base.id, connector->base.name, desc);
+
        return 0;
 }
 

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index b92e0b0..717be9a 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5256,11 +5256,6 @@ static void intel_edp_backlight_setup(struct intel_dp *intel_dp,
 
                if (pipe != PIPE_A && pipe != PIPE_B)
                        pipe = PIPE_A;
-
-               drm_dbg_kms(&i915->drm,
-                           "[CONNECTOR:%d:%s] using pipe %c for initial backlight setup\n",
-                           connector->base.base.id, connector->base.name,
-                           pipe_name(pipe));
        }
 
        intel_backlight_setup(connector, pipe);

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 83af95b..8670b69 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -273,6 +273,11 @@ intel_dp_aux_hdr_disable_backlight(const struct drm_connector_state *conn_state,
        panel->backlight.pwm_funcs->disable(conn_state, intel_backlight_invert_pwm_level(connector, 0));
 }
 
+static const char *dpcd_vs_pwm_str(bool aux)
+{
+       return aux ? "DPCD" : "PWM";
+}
+
 static int
 intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pipe)
 {
@@ -282,11 +287,11 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pi
                &connector->base.display_info.luminance_range;
        int ret;
 
-       if (panel->backlight.edp.intel.sdr_uses_aux) {
-               drm_dbg_kms(&i915->drm, "SDR backlight is controlled through DPCD\n");
-       } else {
-               drm_dbg_kms(&i915->drm, "SDR backlight is controlled through PWM\n");
+       drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] SDR backlight is controlled through %s\n",
+                   connector->base.base.id, connector->base.name,
+                   dpcd_vs_pwm_str(panel->backlight.edp.intel.sdr_uses_aux));
 
+       if (!panel->backlight.edp.intel.sdr_uses_aux) {
                ret = panel->backlight.pwm_funcs->setup(connector, pipe);
                if (ret < 0) {
                        drm_err(&i915->drm,
@@ -303,8 +308,10 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pi
                panel->backlight.min = 0;
        }
 
-       drm_dbg_kms(&i915->drm, "Using backlight range %d..%d\n", panel->backlight.min,
-                   panel->backlight.max);
+       drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Using AUX HDR interface for backlight control (range %d..%d)\n",
+                   connector->base.base.id, connector->base.name,
+                   panel->backlight.min, panel->backlight.max);
+
 
        panel->backlight.level = intel_dp_aux_hdr_get_backlight(connector, pipe);
        panel->backlight.enabled = panel->backlight.level != 0;
@@ -386,6 +393,13 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
        if (ret < 0)
                return ret;
 
+       drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] AUX VESA backlight enable is controlled through %s\n",
+                   connector->base.base.id, connector->base.name,
+                   dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_enable));
+       drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] AUX VESA backlight level is controlled through %s\n",
+                   connector->base.base.id, connector->base.name,
+                   dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_set));
+
        if (!panel->backlight.edp.vesa.info.aux_set || !panel->backlight.edp.vesa.info.aux_enable) {
                ret = panel->backlight.pwm_funcs->setup(connector, pipe);
                if (ret < 0) {
@@ -418,6 +432,9 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
                }
        }
 
+       drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Using AUX VESA interface for backlight control\n",
+                   connector->base.base.id, connector->base.name);
+
        return 0;
 }
 

diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
index 20e466d..0494432 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
@@ -162,6 +162,7 @@ static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state,
 static int dcs_setup_backlight(struct intel_connector *connector,
                               enum pipe unused)
 {
+       struct drm_i915_private *i915 = to_i915(connector->base.dev);
        struct intel_panel *panel = &connector->panel;
 
        if (panel->vbt.backlight.brightness_precision_bits > 8)
@@ -171,6 +172,10 @@ static int dcs_setup_backlight(struct intel_connector *connector,
 
        panel->backlight.level = panel->backlight.max;
 
+       drm_dbg_kms(&i915->drm,
+                   "[CONNECTOR:%d:%s] Using DCS for backlight control\n",
+                   connector->base.base.id, connector->base.name);
+
        return 0;
 }