[PATCH 1/2] drm/i915/lspcon: Avoid unwanted lspcon init and probe failures

[Ankit Nautiyal]

Currently we probe for lspcon, inside lspcon init. Which does 2 things:
detect if lspcon is detected and set the expected LS/PCON mode.

If there is no lspcon connected, the probe expectedly fails and
results in error message. This inturn gets propogated to
lspcon init and we get again error message for lspcon init
failure.

Separate the probe function and avoid displaying error if probe fails.
If probe succeeds, only then start lspcon init and set the expected
LS/PCON mode as first step.

While at it move the drm_err message in lspcon init, instead of the
caller.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c     |  4 ++
 drivers/gpu/drm/i915/display/intel_lspcon.c | 43 ++++++++++++++-------
 drivers/gpu/drm/i915/display/intel_lspcon.h |  1 +
 3 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 4bec8cd7979f..4a77652532ed 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5045,6 +5045,10 @@ intel_dp_connector_register(struct drm_connector *connector)
 	 * ToDo: Clean this up to handle lspcon init and resume more
 	 * efficiently and streamlined.
 	 */
+
+	if (!lspcon_probe(lspcon))
+		return ret;
+
 	if (lspcon_init(dig_port)) {
 		lspcon_detect_hdr_capability(lspcon);
 		if (lspcon->hdr_supported)
diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
index bb3b5355a0d9..e35155058759 100644
--- a/drivers/gpu/drm/i915/display/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
@@ -227,17 +227,13 @@ static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
 	return true;
 }
 
-static bool lspcon_probe(struct intel_lspcon *lspcon)
+bool lspcon_probe(struct intel_lspcon *lspcon)
 {
 	int retry;
 	enum drm_dp_dual_mode_type adaptor_type;
 	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 	struct i2c_adapter *adapter = &intel_dp->aux.ddc;
-	enum drm_lspcon_mode expected_mode;
-
-	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
-			DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
 
 	/* Lets probe the adaptor and check its type */
 	for (retry = 0; retry < 6; retry++) {
@@ -257,6 +253,18 @@ static bool lspcon_probe(struct intel_lspcon *lspcon)
 
 	/* Yay ... got a LSPCON device */
 	drm_dbg_kms(&i915->drm, "LSPCON detected\n");
+	return true;
+}
+
+static bool lspcon_set_expected_mode(struct intel_lspcon *lspcon)
+{
+	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	enum drm_lspcon_mode expected_mode;
+
+	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
+			DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
+
 	lspcon->mode = lspcon_wait_mode(lspcon, expected_mode);
 
 	/*
@@ -653,25 +661,32 @@ bool lspcon_init(struct intel_digital_port *dig_port)
 	lspcon->active = false;
 	lspcon->mode = DRM_LSPCON_MODE_INVALID;
 
-	if (!lspcon_probe(lspcon)) {
-		drm_err(&i915->drm, "Failed to probe lspcon\n");
-		return false;
+	if (!lspcon_set_expected_mode(lspcon)) {
+		drm_err(&i915->drm, "LSPCON Set expected Mode failed\n");
+		goto lspcon_init_failed;
 	}
 
 	if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd) != 0) {
 		drm_err(&i915->drm, "LSPCON DPCD read failed\n");
-		return false;
+		goto lspcon_init_failed;
 	}
 
 	if (!lspcon_detect_vendor(lspcon)) {
 		drm_err(&i915->drm, "LSPCON vendor detection failed\n");
-		return false;
+		goto lspcon_init_failed;
 	}
 
 	connector->ycbcr_420_allowed = true;
 	lspcon->active = true;
 	drm_dbg_kms(&i915->drm, "Success: LSPCON init\n");
+
 	return true;
+
+lspcon_init_failed:
+	drm_err(&i915->drm, "LSPCON init failed on port %c\n",
+		port_name(dig_port->base.port));
+
+	return false;
 }
 
 u32 intel_lspcon_infoframes_enabled(struct intel_encoder *encoder,
@@ -693,11 +708,11 @@ void lspcon_resume(struct intel_digital_port *dig_port)
 		return;
 
 	if (!lspcon->active) {
-		if (!lspcon_init(dig_port)) {
-			drm_err(&i915->drm, "LSPCON init failed on port %c\n",
-				port_name(dig_port->base.port));
+		if (!lspcon_probe(lspcon))
+			return;
+
+		if (!lspcon_init(dig_port))
 			return;
-		}
 	}
 
 	if (lspcon_wake_native_aux_ch(lspcon)) {
diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.h b/drivers/gpu/drm/i915/display/intel_lspcon.h
index e19e10492b05..fa51b0aa1dd1 100644
--- a/drivers/gpu/drm/i915/display/intel_lspcon.h
+++ b/drivers/gpu/drm/i915/display/intel_lspcon.h
@@ -17,6 +17,7 @@ struct intel_lspcon;
 
 bool lspcon_init(struct intel_digital_port *dig_port);
 void lspcon_detect_hdr_capability(struct intel_lspcon *lspcon);
+bool lspcon_probe(struct intel_lspcon *lspcon);
 void lspcon_resume(struct intel_digital_port *dig_port);
 void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon);
 void lspcon_write_infoframe(struct intel_encoder *encoder,
-- 
2.25.1